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Fermat point

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3094: 2700: 4463: 3089:{\displaystyle {\begin{aligned}|\mathbf {a} |&=\mathbf {a\cdot i} =(\mathbf {a} -\mathbf {x} )\mathbf {\,\cdot \,i} +\mathbf {x\cdot i} \leq |\mathbf {a} -\mathbf {x} |+\mathbf {x\cdot i} ,\\|\mathbf {b} |&=\mathbf {b\cdot j} =(\mathbf {b} -\mathbf {x} )\mathbf {\,\cdot \,j} +\mathbf {x\cdot j} \leq |\mathbf {b} -\mathbf {x} |+\mathbf {x\cdot j} ,\\|\mathbf {c} |&=\mathbf {c\cdot k} =(\mathbf {c} -\mathbf {x} )\mathbf {\,\cdot \,k} +\mathbf {x\cdot k} \leq |\mathbf {c} -\mathbf {x} |+\mathbf {x\cdot k} .\end{aligned}}} 501: 138: 5037: 4766: 20: 4787: 4516: 3301: 4392: 4243: 5237: 5032:{\displaystyle {\begin{aligned}&\csc \left(A-{\tfrac {\pi }{3}}\right):\csc \left(B-{\tfrac {\pi }{3}}\right):\csc \left(C-{\tfrac {\pi }{3}}\right)\\&=\sec \left(A+{\tfrac {\pi }{6}}\right):\sec \left(B+{\tfrac {\pi }{6}}\right):\sec \left(C+{\tfrac {\pi }{6}}\right).\end{aligned}}} 4761:{\displaystyle {\begin{aligned}&\csc \left(A+{\tfrac {\pi }{3}}\right):\csc \left(B+{\tfrac {\pi }{3}}\right):\csc \left(C+{\tfrac {\pi }{3}}\right)\\&=\sec \left(A-{\tfrac {\pi }{6}}\right):\sec \left(B-{\tfrac {\pi }{6}}\right):\sec \left(C-{\tfrac {\pi }{6}}\right).\end{aligned}}} 3489: 3119: 5567: 5415: 4258: 2642: 3958: 955: 715:
A key result that will be used is the dogleg rule, which asserts that if a triangle and a polygon have one side in common and the rest of the triangle lies inside the polygon then the triangle has a shorter perimeter than the polygon:
3810: 5054: 3348: 3296:{\displaystyle |\mathbf {a} |+|\mathbf {b} |+|\mathbf {c} |\leq |\mathbf {a} -\mathbf {x} |+|\mathbf {b} -\mathbf {x} |+|\mathbf {c} -\mathbf {x} |+\mathbf {x} \cdot (\mathbf {i} +\mathbf {j} +\mathbf {k} ).} 5444: 5292: 5757:. He solved the problem in a similar way to Fermat's, albeit using the intersection of the circumcircles of the three regular triangles instead. His pupil, Viviani, published the solution in 1659. 4387:{\displaystyle {\tfrac {\partial L}{\partial x}},{\tfrac {\partial L}{\partial y}},{\tfrac {\partial L}{\partial z}},{\tfrac {\partial L}{\partial \alpha }},{\tfrac {\partial L}{\partial \beta }}} 4792: 4521: 2705: 2001: 3629: 119:
For each isosceles triangle draw a circle, in each case with center on the new vertex of the isosceles triangle and with radius equal to each of the two new sides of that isosceles triangle.
2552: 2459: 1081: 2315: 1536: 6064: 606: 1673: 1366: 1221: 2403: 2354: 1624: 1575: 1138: 4238:{\displaystyle L=x+y+z+\lambda _{1}(x^{2}+y^{2}-2xy\cos(\alpha )-a^{2})+\lambda _{2}(y^{2}+z^{2}-2yz\cos(\beta )-b^{2})+\lambda _{3}(z^{2}+x^{2}-2zx\cos(\alpha +\beta )-c^{2})} 2510: 666: 1451: 2197: 1769: 1717: 1495: 702: 2230: 483:. So, the lines joining the centers of the circles also intersect at 60° angles. Therefore, the centers of the circles form an equilateral triangle. This is known as 1017: 1795: 745: 47:, is a point such that the sum of the three distances from each of the three vertices of the triangle to the point is the smallest possible or, equivalently, the 5737:. However these different names can be confusing and are perhaps best avoided. The problem is that much of the literature blurs the distinction between the 968:. Associate each vertex with its remote zone; that is, the half-plane beyond the (extended) opposite side. These 3 zones cover the entire plane except for 5232:{\displaystyle 1-u+uvw\sec \left(A-{\tfrac {\pi }{6}}\right):1-v+uvw\sec \left(B-{\tfrac {\pi }{6}}\right):1-w+uvw\sec \left(C-{\tfrac {\pi }{6}}\right)} 3740: 3815:
the third inequality still holds, the other two inequalities are unchanged. The proof now continues as above (adding the three inequalities and using
3484:{\displaystyle |\mathbf {a} |+|\mathbf {b} |+|\mathbf {c} |\leq |\mathbf {a} -\mathbf {x} |+|\mathbf {b} -\mathbf {x} |+|\mathbf {c} -\mathbf {x} |} 116:, with base the side in question, 30-degree angles at the base, and the third vertex of each isosceles triangle lying outside the original triangle. 6165: 6160: 6134: 6071: 23:
Fig 1. Construction of the first isogonic center, X(13). When no angle of the triangle exceeds 120°, this point is the Fermat point.
5929: 5910: 5891: 5872: 5562:{\displaystyle \sin \left(A-{\tfrac {\pi }{3}}\right):\sin \left(B-{\tfrac {\pi }{3}}\right):\sin \left(C-{\tfrac {\pi }{3}}\right).} 5410:{\displaystyle \sin \left(A+{\tfrac {\pi }{3}}\right):\sin \left(B+{\tfrac {\pi }{3}}\right):\sin \left(C+{\tfrac {\pi }{3}}\right).} 6129: 129:
In what follows "Case 1" means the triangle has an angle exceeding 120°. "Case 2" means no angle of the triangle exceeds 120°.
6170: 1863: 6144: 6028: 3506: 6189: 6114: 2637:{\displaystyle {\overrightarrow {OA}},\ {\overrightarrow {OB}},\ {\overrightarrow {OC}},\ {\overrightarrow {OX}}} 6005: 6015: 2247: 1500: 522: 6010: 1285: 2408: 1022: 6109: 126:
When a triangle has an angle greater than 120°, the Fermat point is sited at the obtuse-angled vertex.
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intersect. This point is commonly called the first isogonic center. Carry out the same exercise with
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Another approach to finding the point within a triangle, from which the sum of the distances to the
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or Fermat–Weber point, the point minimizing the sum of distances to more than three given points.
4454:. However the elimination is a long and tedious business, and the end result covers only Case 2. 2202: 5806: 6181: 5946: 5754: 56: 449:
The lines joining the centers of the circles in Fig. 2 are perpendicular to the line segments
299: 264: 6104: 5609: 4500: 1774: 484: 194: 6034: 5964: 950:{\displaystyle {\text{perimeter}}>|AB|+|AX|+|XB|=|AB|+|AC|+|CX|+|XB|\geq |AB|+|AC|+|BC|.} 5850: 5698: 3865: 91: 67: 5926: 5907: 5888: 5869: 991: 122:
The intersection inside the original triangle between the two circles is the Fermat point.
8: 6038: 5772: 5672: 3948:. Using the method of Lagrange multipliers we have to find the minimum of the Lagrangian 737: 6139: 6119: 5838: 113: 28: 4462: 5977: 5668: 3857: 708:
will denote the points inside the triangle and will be taken to include its boundary
98: 6080: 5834: 5830: 5818: 5766: 5428: 5276: 3805:{\displaystyle |\mathbf {0} |\leq |\mathbf {0} -\mathbf {x} |+\mathbf {x\cdot k} ,} 355: 238: 168: 63: 52: 48: 5980: 6044: 6023: 5933: 5914: 5895: 5876: 5846: 5782: 5777: 307: 224: 5959:
Christopher J. Bradley and Geoff C. Smith, "The locations of triangle centers",
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We draw lines from the point within the triangle to its vertices and call them
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of the three vertices. It is so named because this problem was first raised by
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The Fermat point of a triangle with largest angle at most 120° is simply its
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If such a point exists then it will be the Fermat point. In what follows
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meet at angles of 120°. Nevertheless, it is easily fixed by redefining
5985: 500: 463:. For example, the line joining the center of the circle containing 137: 5745:
whereas it is only in Case 2 above that they are actually the same.
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of the three constructed equilateral triangles are concurrent at
4486:(13) are all equal to 120° (Case 2), or 60°, 60°, 120° (Case 1). 4475:
When the largest angle of the triangle is not larger than 120°,
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is equilateral and has the orientation shown. Then the triangle
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on each of two arbitrarily chosen sides of the given triangle.
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the Fermat point is coincident with the first isogonic center
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punctured at its own center, and could be any point therein.
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Interactive sketch generalizes the Fermat-Torricelli point.
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Triangle center minimizing sum of distances to each vertex
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http://forumgeom.fau.edu/FG2006volume6/FG200607index.html
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so these two triangles are congruent and it follows that
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This question was proposed by Fermat, as a challenge to
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The two isogonic centers are the intersections of three
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because the second is a 60° rotation of the first about
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Trilinear coordinates for the second isogonic center,
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whose paired vertices are the vertices of the triangle
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Without loss of generality, suppose that the angle at
391:. However it is easily modified to cover Case 1. Then 112:
On each of two arbitrarily chosen sides, construct an
5648:. The three lines meet at the Euler infinity point, 5447: 5295: 5057: 4790: 4519: 4482:
The angles subtended by the sides of the triangle at
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Cut The Knot - The Fermat Point and Generalizations
3648:This argument fails when the triangle has an angle 5561: 5409: 5231: 5031: 4760: 4386: 4237: 3804: 3623: 3483: 3295: 3088: 2636: 2549:be any five points in a plane. Denote the vectors 2504: 2453: 2397: 2348: 2309: 2224: 2191: 1996:{\displaystyle d(P)=|PA|+|PB|+|PC|=|AP|+|PQ|+|QD|} 1995: 1789: 1763: 1711: 1667: 1618: 1569: 1530: 1489: 1445: 1360: 1215: 1132: 1075: 1011: 949: 696: 660: 600: 3860:of the triangle is minimal, is to use one of the 3624:{\displaystyle |OA|+|OB|+|OC|\leq |XA|+|XB|+|XC|} 1807:the Fermat point lies at the obtuse-angled vertex 6204: 160:attached to the sides of the arbitrary triangle 101:to the opposite vertex of the original triangle. 608:The aim of this section is to identify a point 490: 241:(they lie on a circle). Similarly, the points 141:Fig 2. Geometry of the first isogonic center. 4255:Equating each of the five partial derivatives 4252:are the lengths of the sides of the triangle. 1234:is ≥ 120°. Construct the equilateral triangle 976:clearly lies in either one or two of them. If 6065: 1813:Case 2. The triangle has no angle ≥ 120°. 1226:Case 1. The triangle has an angle ≥ 120°. 364:This proof applies only in Case 2, since if 104:The two lines intersect at the Fermat point. 6161:List of things named after Pierre de Fermat 5045:Trilinear coordinates for the Fermat point: 3717:because the angle between the unit vectors 6072: 6058: 5817: 3889:. Also, let the lengths of these lines be 736:. Then the polygon's perimeter is, by the 5686:(14) meets the Euler line at midpoint of 5575:The following triangles are equilateral: 3020: 3016: 2894: 2890: 2768: 2764: 1832:, and construct the equilateral triangle 383:which switches the relative positions of 62:The Fermat point gives a solution to the 4461: 499: 470:and the center of the circle containing 136: 108:An alternative method is the following: 18: 6135:Fermat's theorem on sums of two squares 6045:A practical example of the Fermat point 3851: 2006:which is simply the length of the path 1368:which is simply the length of the path 495: 145:Fig. 2 shows the equilateral triangles 6205: 6166:Wiles's proof of Fermat's Last Theorem 5953: 5944: 2310:{\displaystyle d(P_{0})=|AD|<d(P).} 358:(they intersect at a single point). 179:and cut one another at angles of 60°. 167:. Here is a proof using properties of 6053: 5976: 3864:methods; specifically, the method of 1531:{\displaystyle P\in \Delta ,P\neq A.} 1083:by the dogleg rule. Alternatively if 504:Fig 3. Geometry of the Fermat point 6130:Fermat's theorem (stationary points) 6079: 3893:respectively. Let the angle between 3833:) to reach the same conclusion that 601:{\displaystyle d(P)=|PA|+|PB|+|PC|.} 175:in Fig 2 all intersect at the point 132: 5729:respectively. Alternatives are the 1817:Construct the equilateral triangle 1361:{\displaystyle d(P)=|CP|+|PQ|+|QF|} 86:, which is constructed as follows: 13: 6029:The Wolfram Demonstrations Project 5947:"Encyclopedia of Triangle Centers" 5938: 5697:The Fermat point lies in the open 4374: 4366: 4349: 4341: 4324: 4316: 4299: 4291: 4274: 4266: 2540: 2454:{\displaystyle d(P_{0})\leq d(P')} 2343: 1564: 1510: 1271:is a 60° rotation of the triangle 1076:{\displaystyle d(P')=d(A)<d(P)} 988:zones’ intersection) then setting 477:, is perpendicular to the segment 14: 6224: 5998: 6171:Fermat's Last Theorem in fiction 6035:Fermat-Torricelli generalization 5927:Encyclopedia of Triangle Centers 5908:Encyclopedia of Triangle Centers 5889:Encyclopedia of Triangle Centers 5870:Encyclopedia of Triangle Centers 3795: 3789: 3776: 3768: 3750: 3472: 3464: 3446: 3438: 3420: 3412: 3394: 3376: 3358: 3283: 3275: 3267: 3256: 3243: 3235: 3217: 3209: 3191: 3183: 3165: 3147: 3129: 3075: 3069: 3056: 3048: 3035: 3029: 3021: 3008: 3000: 2989: 2983: 2966: 2949: 2943: 2930: 2922: 2909: 2903: 2895: 2882: 2874: 2863: 2857: 2840: 2823: 2817: 2804: 2796: 2783: 2777: 2769: 2756: 2748: 2737: 2731: 2714: 2505:{\displaystyle d(P_{0})<d(P)} 732:to cut the polygon at the point 661:{\displaystyle d(P_{0})<d(P)} 376:lies inside the circumcircle of 6145:Fermat's right triangle theorem 6115:Fermat polygonal number theorem 4503:for the first isogonic center, 1446:{\displaystyle |AC|+|AF|=d(A).} 302:, this implies that the points 73: 5969: 5919: 5900: 5881: 5862: 5835:10.1080/0025570X.1994.11996210 5811: 5800: 4232: 4216: 4204: 4160: 4144: 4128: 4122: 4078: 4062: 4046: 4040: 3996: 3841:) must be the Fermat point of 3781: 3763: 3755: 3745: 3617: 3606: 3598: 3587: 3579: 3568: 3560: 3549: 3541: 3530: 3522: 3511: 3477: 3459: 3451: 3433: 3425: 3407: 3399: 3389: 3381: 3371: 3363: 3353: 3287: 3263: 3248: 3230: 3222: 3204: 3196: 3178: 3170: 3160: 3152: 3142: 3134: 3124: 3061: 3043: 3012: 2996: 2971: 2961: 2935: 2917: 2886: 2870: 2845: 2835: 2809: 2791: 2760: 2744: 2719: 2709: 2499: 2493: 2484: 2471: 2448: 2437: 2428: 2415: 2392: 2386: 2377: 2366: 2301: 2295: 2285: 2274: 2267: 2254: 2182: 2171: 2154: 1989: 1978: 1970: 1959: 1951: 1940: 1932: 1921: 1913: 1902: 1894: 1883: 1876: 1870: 1758: 1752: 1743: 1737: 1706: 1700: 1691: 1685: 1668:{\displaystyle d(A)\leq d(P')} 1662: 1651: 1642: 1636: 1613: 1607: 1598: 1587: 1484: 1478: 1469: 1463: 1437: 1431: 1421: 1410: 1402: 1391: 1354: 1343: 1335: 1324: 1316: 1305: 1298: 1292: 1216:{\displaystyle d(P')<d(P).} 1207: 1201: 1192: 1181: 1127: 1121: 1112: 1101: 1070: 1064: 1055: 1049: 1040: 1029: 940: 929: 921: 910: 902: 891: 883: 872: 864: 853: 845: 834: 826: 815: 807: 796: 788: 777: 769: 758: 655: 649: 640: 627: 591: 580: 572: 561: 553: 542: 535: 529: 1: 5793: 4457: 2398:{\displaystyle d(P')<d(P)} 2349:{\displaystyle P'\in \Omega } 2192:{\displaystyle d(P_{0}=|AD|.} 2049:. By the angular restriction 1619:{\displaystyle d(P')<d(P)} 1570:{\displaystyle P'\in \Omega } 1376:is constrained to lie within 1133:{\displaystyle d(P')<d(P)} 1087:is in only one zone, say the 508:Given any Euclidean triangle 306:are concyclic. So, using the 171:to show that the three lines 1764:{\displaystyle d(A)<d(P)} 1712:{\displaystyle d(A)<d(P)} 1490:{\displaystyle d(A)<d(P)} 697:{\displaystyle P\neq P_{0}.} 491:Location of the Fermat point 7: 6011:Encyclopedia of Mathematics 6006:"Fermat-Torricelli problem" 5760: 5721:(14) are also known as the 3734:which exceeds 120°. Since 2225:{\displaystyle P\neq P_{0}} 726:is the common side, extend 10: 6229: 5748: 5705: 5423:The isogonal conjugate of 5271:The isogonal conjugate of 3656:because there is no point 97:Draw a line from each new 6153: 6087: 6039:Dynamic Geometry Sketches 5644:(16) are parallel to the 5619:Circumcevian triangle of 4479:(13) is the Fermat point. 3952:, which is expressed as: 3925:. Then the angle between 3862:mathematical optimization 2676:be the unit vectors from 344:lies on the line segment 223:. By the converse of the 5247:respectively denote the 4394:to zero and eliminating 6110:Fermat's little theorem 5932:April 19, 2012, at the 5913:April 19, 2012, at the 5894:April 19, 2012, at the 5875:April 19, 2012, at the 5429:second isodynamic point 3638:is the Fermat point of 3324:at angles of 120° then 2529:is the Fermat point of 1801:is the Fermat point of 1790:{\displaystyle P\neq A} 1144:is the intersection of 515:and an arbitrary point 310:applied to the segment 308:inscribed angle theorem 300:inscribed angle theorem 265:inscribed angle theorem 227:applied to the segment 225:inscribed angle theorem 55:in a private letter to 45:Fermat–Torricelli point 6193:(popular science book) 5755:Evangelista Torricelli 5588:Antipedal triangle of 5563: 5411: 5277:first isodynamic point 5233: 5033: 4762: 4471: 4388: 4239: 3806: 3625: 3485: 3297: 3090: 2662:respectively, and let 2638: 2506: 2455: 2399: 2350: 2311: 2226: 2193: 2144:is a straight line so 2092:must lie somewhere on 1997: 1791: 1765: 1713: 1669: 1620: 1571: 1532: 1491: 1447: 1362: 1217: 1134: 1077: 1013: 951: 698: 662: 602: 505: 142: 57:Evangelista Torricelli 24: 6190:Fermat's Last Theorem 6095:Fermat's Last Theorem 5735:negative Fermat point 5731:positive Fermat point 5610:Circumcevian triangle 5564: 5412: 5234: 5034: 4763: 4501:Trilinear coordinates 4465: 4389: 4240: 3807: 3626: 3486: 3298: 3091: 2639: 2507: 2456: 2400: 2351: 2325:. From above a point 2312: 2227: 2194: 2072:is a 60° rotation of 2040:, and find the point 1998: 1846:is a 60° rotation of 1792: 1766: 1714: 1670: 1621: 1572: 1546:. From above a point 1533: 1492: 1448: 1363: 1257:so that the triangle 1218: 1162:there exists a point 1135: 1078: 1014: 964:be any point outside 952: 699: 663: 603: 503: 140: 80:first isogonic center 68:Steiner tree problems 22: 5823:Mathematics Magazine 5699:orthocentroidal disk 5445: 5293: 5055: 4788: 4517: 4259: 3959: 3866:Lagrange multipliers 3852:Lagrange multipliers 3741: 3507: 3349: 3120: 2701: 2553: 2465: 2409: 2360: 2329: 2248: 2203: 2148: 1864: 1828:be any point inside 1775: 1731: 1679: 1630: 1581: 1550: 1501: 1457: 1387: 1286: 1175: 1095: 1023: 1012:{\displaystyle P'=A} 992: 746: 672: 621: 523: 496:Traditional geometry 92:equilateral triangle 6182:Fermat's Last Tango 5963:6 (2006), 57--70. 5961:Forum Geometricorum 5945:Kimberling, Clark. 5925:Entry X(16) in the 5906:Entry X(15) in the 5887:Entry X(14) in the 5868:Entry X(13) in the 5727:second Fermat point 3500:. In other words, 2019:be the point where 980:is in two (say the 738:triangle inequality 6120:Fermat pseudoprime 6105:Fermat's principle 6027:by Chris Boucher, 5978:Weisstein, Eric W. 5743:first Fermat point 5723:first Fermat point 5602:Pedal triangle of 5595:Pedal triangle of 5579:antipedal triangle 5559: 5549: 5512: 5475: 5407: 5397: 5360: 5323: 5229: 5222: 5164: 5106: 5029: 5027: 5015: 4978: 4941: 4897: 4860: 4823: 4758: 4756: 4744: 4707: 4670: 4626: 4589: 4552: 4472: 4384: 4382: 4357: 4332: 4307: 4282: 4235: 3802: 3621: 3481: 3293: 3086: 3084: 2634: 2533:. In other words, 2502: 2451: 2395: 2346: 2307: 2222: 2189: 1993: 1805:. In other words, 1787: 1761: 1709: 1665: 1616: 1567: 1528: 1487: 1443: 1358: 1253:itself) construct 1241:and for any point 1213: 1130: 1073: 1009: 947: 694: 658: 598: 506: 485:Napoleon's Theorem 143: 114:isosceles triangle 70:for three points. 39:, also called the 29:Euclidean geometry 25: 6200: 6199: 5819:Kimberling, Clark 5669:nine-point center 5548: 5511: 5474: 5396: 5359: 5322: 5249:Boolean variables 5221: 5163: 5105: 5014: 4977: 4940: 4896: 4859: 4822: 4743: 4706: 4669: 4625: 4588: 4551: 4417:eventually gives 4381: 4356: 4331: 4306: 4281: 3837:(or in this case 2632: 2618: 2611: 2597: 2590: 2576: 2569: 2356:exists such that 2321:to range outside 1797:which means that 1577:exists such that 1542:to range outside 752: 350:. So, the lines 133:Location of X(13) 59:, who solved it. 6220: 6213:Triangle centers 6081:Pierre de Fermat 6074: 6067: 6060: 6051: 6050: 6019: 5992: 5991: 5990: 5973: 5967: 5957: 5951: 5950: 5942: 5936: 5923: 5917: 5904: 5898: 5885: 5879: 5866: 5860: 5854: 5815: 5809: 5804: 5773:Lester's theorem 5767:Geometric median 5712:isogonic centers 5568: 5566: 5565: 5560: 5555: 5551: 5550: 5541: 5518: 5514: 5513: 5504: 5481: 5477: 5476: 5467: 5416: 5414: 5413: 5408: 5403: 5399: 5398: 5389: 5366: 5362: 5361: 5352: 5329: 5325: 5324: 5315: 5265: 5246: 5238: 5236: 5235: 5230: 5228: 5224: 5223: 5214: 5170: 5166: 5165: 5156: 5112: 5108: 5107: 5098: 5038: 5036: 5035: 5030: 5028: 5021: 5017: 5016: 5007: 4984: 4980: 4979: 4970: 4947: 4943: 4942: 4933: 4907: 4903: 4899: 4898: 4889: 4866: 4862: 4861: 4852: 4829: 4825: 4824: 4815: 4794: 4767: 4765: 4764: 4759: 4757: 4750: 4746: 4745: 4736: 4713: 4709: 4708: 4699: 4676: 4672: 4671: 4662: 4636: 4632: 4628: 4627: 4618: 4595: 4591: 4590: 4581: 4558: 4554: 4553: 4544: 4523: 4453: 4442: 4427: 4416: 4393: 4391: 4390: 4385: 4383: 4380: 4372: 4364: 4358: 4355: 4347: 4339: 4333: 4330: 4322: 4314: 4308: 4305: 4297: 4289: 4283: 4280: 4272: 4264: 4251: 4244: 4242: 4241: 4236: 4231: 4230: 4185: 4184: 4172: 4171: 4159: 4158: 4143: 4142: 4103: 4102: 4090: 4089: 4077: 4076: 4061: 4060: 4021: 4020: 4008: 4007: 3995: 3994: 3951: 3947: 3936: 3930: 3924: 3920: 3914: 3908: 3904: 3898: 3892: 3888: 3847: 3840: 3836: 3832: 3811: 3809: 3808: 3803: 3798: 3784: 3779: 3771: 3766: 3758: 3753: 3748: 3733: 3726: 3716: 3714: 3706: 3696: 3692: 3688: 3673: 3659: 3655: 3644: 3637: 3630: 3628: 3627: 3622: 3620: 3609: 3601: 3590: 3582: 3571: 3563: 3552: 3544: 3533: 3525: 3514: 3499: 3490: 3488: 3487: 3482: 3480: 3475: 3467: 3462: 3454: 3449: 3441: 3436: 3428: 3423: 3415: 3410: 3402: 3397: 3392: 3384: 3379: 3374: 3366: 3361: 3356: 3341: 3323: 3319: 3302: 3300: 3299: 3294: 3286: 3278: 3270: 3259: 3251: 3246: 3238: 3233: 3225: 3220: 3212: 3207: 3199: 3194: 3186: 3181: 3173: 3168: 3163: 3155: 3150: 3145: 3137: 3132: 3127: 3112: 3095: 3093: 3092: 3087: 3085: 3078: 3064: 3059: 3051: 3046: 3038: 3024: 3011: 3003: 2992: 2974: 2969: 2964: 2952: 2938: 2933: 2925: 2920: 2912: 2898: 2885: 2877: 2866: 2848: 2843: 2838: 2826: 2812: 2807: 2799: 2794: 2786: 2772: 2759: 2751: 2740: 2722: 2717: 2712: 2693: 2679: 2675: 2661: 2643: 2641: 2640: 2635: 2633: 2628: 2620: 2616: 2612: 2607: 2599: 2595: 2591: 2586: 2578: 2574: 2570: 2565: 2557: 2548: 2532: 2528: 2519: 2515: 2511: 2509: 2508: 2503: 2483: 2482: 2461:it follows that 2460: 2458: 2457: 2452: 2447: 2427: 2426: 2404: 2402: 2401: 2396: 2376: 2355: 2353: 2352: 2347: 2339: 2324: 2320: 2316: 2314: 2313: 2308: 2288: 2277: 2266: 2265: 2243: 2239: 2235: 2231: 2229: 2228: 2223: 2221: 2220: 2198: 2196: 2195: 2190: 2185: 2174: 2166: 2165: 2143: 2125: 2121: 2112: 2104:it follows that 2103: 2095: 2091: 2082: 2078: 2071: 2064: 2057: 2048: 2039: 2036:as you did with 2035: 2026: 2022: 2018: 2009: 2002: 2000: 1999: 1994: 1992: 1981: 1973: 1962: 1954: 1943: 1935: 1924: 1916: 1905: 1897: 1886: 1856: 1852: 1845: 1838: 1831: 1827: 1823: 1804: 1800: 1796: 1794: 1793: 1788: 1770: 1768: 1767: 1762: 1726: 1722: 1718: 1716: 1715: 1710: 1675:it follows that 1674: 1672: 1671: 1666: 1661: 1625: 1623: 1622: 1617: 1597: 1576: 1574: 1573: 1568: 1560: 1545: 1541: 1537: 1535: 1534: 1529: 1496: 1494: 1493: 1488: 1452: 1450: 1449: 1444: 1424: 1413: 1405: 1394: 1382: 1375: 1371: 1367: 1365: 1364: 1359: 1357: 1346: 1338: 1327: 1319: 1308: 1281: 1277: 1270: 1263: 1256: 1252: 1248: 1244: 1240: 1233: 1222: 1220: 1219: 1214: 1191: 1169: 1165: 1161: 1157: 1154:for every point 1151: 1147: 1143: 1139: 1137: 1136: 1131: 1111: 1090: 1086: 1082: 1080: 1079: 1074: 1039: 1018: 1016: 1015: 1010: 1002: 987: 983: 979: 975: 971: 967: 963: 956: 954: 953: 948: 943: 932: 924: 913: 905: 894: 886: 875: 867: 856: 848: 837: 829: 818: 810: 799: 791: 780: 772: 761: 753: 750: 735: 731: 730: 725: 724: 711: 707: 703: 701: 700: 695: 690: 689: 667: 665: 664: 659: 639: 638: 616: 607: 605: 604: 599: 594: 583: 575: 564: 556: 545: 518: 514: 482: 481: 476: 469: 462: 461: 457: 453: 445: 441: 437: 423:is concyclic so 422: 418: 402: 390: 386: 382: 375: 371: 353: 349: 348: 343: 339: 327: 315: 314: 305: 297: 285: 274: 262: 254: 244: 236: 232: 231: 222: 211: 200: 192: 178: 174: 169:concyclic points 166: 159: 64:geometric median 49:geometric median 41:Torricelli point 6228: 6227: 6223: 6222: 6221: 6219: 6218: 6217: 6203: 6202: 6201: 6196: 6149: 6140:Fermat's spiral 6083: 6078: 6004: 6001: 5996: 5995: 5981:"Fermat Points" 5974: 5970: 5958: 5954: 5943: 5939: 5934:Wayback Machine 5924: 5920: 5915:Wayback Machine 5905: 5901: 5896:Wayback Machine 5886: 5882: 5877:Wayback Machine 5867: 5863: 5858: 5816: 5812: 5805: 5801: 5796: 5783:Napoleon points 5778:Triangle center 5763: 5751: 5708: 5539: 5532: 5528: 5502: 5495: 5491: 5465: 5458: 5454: 5446: 5443: 5442: 5387: 5380: 5376: 5350: 5343: 5339: 5313: 5306: 5302: 5294: 5291: 5290: 5251: 5244: 5212: 5205: 5201: 5154: 5147: 5143: 5096: 5089: 5085: 5056: 5053: 5052: 5026: 5025: 5005: 4998: 4994: 4968: 4961: 4957: 4931: 4924: 4920: 4905: 4904: 4887: 4880: 4876: 4850: 4843: 4839: 4813: 4806: 4802: 4791: 4789: 4786: 4785: 4755: 4754: 4734: 4727: 4723: 4697: 4690: 4686: 4660: 4653: 4649: 4634: 4633: 4616: 4609: 4605: 4579: 4572: 4568: 4542: 4535: 4531: 4520: 4518: 4515: 4514: 4460: 4444: 4429: 4418: 4415: 4408: 4401: 4395: 4373: 4365: 4362: 4348: 4340: 4337: 4323: 4315: 4312: 4298: 4290: 4287: 4273: 4265: 4262: 4260: 4257: 4256: 4249: 4226: 4222: 4180: 4176: 4167: 4163: 4154: 4150: 4138: 4134: 4098: 4094: 4085: 4081: 4072: 4068: 4056: 4052: 4016: 4012: 4003: 3999: 3990: 3986: 3960: 3957: 3956: 3949: 3938: 3932: 3926: 3922: 3916: 3910: 3906: 3900: 3894: 3890: 3876: 3854: 3842: 3838: 3834: 3816: 3788: 3780: 3775: 3767: 3762: 3754: 3749: 3744: 3742: 3739: 3738: 3728: 3718: 3710: 3708: 3698: 3694: 3690: 3675: 3661: 3657: 3649: 3639: 3635: 3616: 3605: 3597: 3586: 3578: 3567: 3559: 3548: 3540: 3529: 3521: 3510: 3508: 3505: 3504: 3495: 3476: 3471: 3463: 3458: 3450: 3445: 3437: 3432: 3424: 3419: 3411: 3406: 3398: 3393: 3388: 3380: 3375: 3370: 3362: 3357: 3352: 3350: 3347: 3346: 3325: 3321: 3307: 3282: 3274: 3266: 3255: 3247: 3242: 3234: 3229: 3221: 3216: 3208: 3203: 3195: 3190: 3182: 3177: 3169: 3164: 3159: 3151: 3146: 3141: 3133: 3128: 3123: 3121: 3118: 3117: 3100: 3083: 3082: 3068: 3060: 3055: 3047: 3042: 3028: 3015: 3007: 2999: 2982: 2975: 2970: 2965: 2960: 2957: 2956: 2942: 2934: 2929: 2921: 2916: 2902: 2889: 2881: 2873: 2856: 2849: 2844: 2839: 2834: 2831: 2830: 2816: 2808: 2803: 2795: 2790: 2776: 2763: 2755: 2747: 2730: 2723: 2718: 2713: 2708: 2704: 2702: 2699: 2698: 2681: 2677: 2663: 2645: 2621: 2619: 2600: 2598: 2579: 2577: 2558: 2556: 2554: 2551: 2550: 2546: 2543: 2541:Vector analysis 2530: 2527: 2521: 2517: 2513: 2478: 2474: 2466: 2463: 2462: 2440: 2422: 2418: 2410: 2407: 2406: 2369: 2361: 2358: 2357: 2332: 2330: 2327: 2326: 2322: 2318: 2284: 2273: 2261: 2257: 2249: 2246: 2245: 2241: 2237: 2233: 2216: 2212: 2204: 2201: 2200: 2181: 2170: 2161: 2157: 2149: 2146: 2145: 2139: 2133: 2127: 2123: 2120: 2114: 2111: 2105: 2097: 2093: 2090: 2084: 2080: 2073: 2066: 2059: 2056: 2050: 2047: 2041: 2037: 2034: 2028: 2024: 2020: 2017: 2011: 2007: 1988: 1977: 1969: 1958: 1950: 1939: 1931: 1920: 1912: 1901: 1893: 1882: 1865: 1862: 1861: 1854: 1847: 1840: 1833: 1829: 1825: 1818: 1802: 1798: 1776: 1773: 1772: 1732: 1729: 1728: 1724: 1720: 1680: 1677: 1676: 1654: 1631: 1628: 1627: 1590: 1582: 1579: 1578: 1553: 1551: 1548: 1547: 1543: 1539: 1502: 1499: 1498: 1458: 1455: 1454: 1420: 1409: 1401: 1390: 1388: 1385: 1384: 1377: 1373: 1369: 1353: 1342: 1334: 1323: 1315: 1304: 1287: 1284: 1283: 1279: 1272: 1265: 1258: 1254: 1250: 1246: 1242: 1235: 1231: 1184: 1176: 1173: 1172: 1167: 1163: 1159: 1155: 1149: 1145: 1141: 1104: 1096: 1093: 1092: 1088: 1084: 1032: 1024: 1021: 1020: 995: 993: 990: 989: 985: 981: 977: 973: 969: 965: 961: 939: 928: 920: 909: 901: 890: 882: 871: 863: 852: 844: 833: 825: 814: 806: 795: 787: 776: 768: 757: 749: 747: 744: 743: 733: 728: 727: 722: 721: 709: 705: 685: 681: 673: 670: 669: 634: 630: 622: 619: 618: 615: 609: 590: 579: 571: 560: 552: 541: 524: 521: 520: 516: 509: 498: 493: 479: 478: 471: 464: 459: 455: 451: 450: 443: 439: 424: 420: 404: 392: 388: 384: 377: 373: 365: 351: 346: 345: 341: 329: 317: 312: 311: 303: 287: 279: 268: 256: 248: 245:are concyclic. 242: 234: 229: 228: 213: 202: 198: 183: 176: 172: 161: 146: 135: 76: 17: 12: 11: 5: 6226: 6216: 6215: 6198: 6197: 6195: 6194: 6186: 6185:(2000 musical) 6178: 6173: 6168: 6163: 6157: 6155: 6151: 6150: 6148: 6147: 6142: 6137: 6132: 6127: 6122: 6117: 6112: 6107: 6102: 6097: 6091: 6089: 6085: 6084: 6077: 6076: 6069: 6062: 6054: 6048: 6047: 6042: 6032: 6020: 6000: 5999:External links 5997: 5994: 5993: 5968: 5952: 5937: 5918: 5899: 5880: 5861: 5856: 5829:(3): 163–187. 5810: 5798: 5797: 5795: 5792: 5791: 5790: 5785: 5780: 5775: 5770: 5762: 5759: 5750: 5747: 5707: 5704: 5703: 5702: 5695: 5676: 5653: 5626: 5625: 5624: 5617: 5607: 5600: 5593: 5586: 5572: 5571: 5570: 5569: 5558: 5554: 5547: 5544: 5538: 5535: 5531: 5527: 5524: 5521: 5517: 5510: 5507: 5501: 5498: 5494: 5490: 5487: 5484: 5480: 5473: 5470: 5464: 5461: 5457: 5453: 5450: 5437: 5436: 5420: 5419: 5418: 5417: 5406: 5402: 5395: 5392: 5386: 5383: 5379: 5375: 5372: 5369: 5365: 5358: 5355: 5349: 5346: 5342: 5338: 5335: 5332: 5328: 5321: 5318: 5312: 5309: 5305: 5301: 5298: 5285: 5284: 5268: 5267: 5241: 5240: 5239: 5227: 5220: 5217: 5211: 5208: 5204: 5200: 5197: 5194: 5191: 5188: 5185: 5182: 5179: 5176: 5173: 5169: 5162: 5159: 5153: 5150: 5146: 5142: 5139: 5136: 5133: 5130: 5127: 5124: 5121: 5118: 5115: 5111: 5104: 5101: 5095: 5092: 5088: 5084: 5081: 5078: 5075: 5072: 5069: 5066: 5063: 5060: 5047: 5046: 5042: 5041: 5040: 5039: 5024: 5020: 5013: 5010: 5004: 5001: 4997: 4993: 4990: 4987: 4983: 4976: 4973: 4967: 4964: 4960: 4956: 4953: 4950: 4946: 4939: 4936: 4930: 4927: 4923: 4919: 4916: 4913: 4910: 4908: 4906: 4902: 4895: 4892: 4886: 4883: 4879: 4875: 4872: 4869: 4865: 4858: 4855: 4849: 4846: 4842: 4838: 4835: 4832: 4828: 4821: 4818: 4812: 4809: 4805: 4801: 4798: 4795: 4793: 4780: 4779: 4771: 4770: 4769: 4768: 4753: 4749: 4742: 4739: 4733: 4730: 4726: 4722: 4719: 4716: 4712: 4705: 4702: 4696: 4693: 4689: 4685: 4682: 4679: 4675: 4668: 4665: 4659: 4656: 4652: 4648: 4645: 4642: 4639: 4637: 4635: 4631: 4624: 4621: 4615: 4612: 4608: 4604: 4601: 4598: 4594: 4587: 4584: 4578: 4575: 4571: 4567: 4564: 4561: 4557: 4550: 4547: 4541: 4538: 4534: 4530: 4527: 4524: 4522: 4509: 4508: 4498: 4487: 4480: 4468:vesicae piscis 4459: 4456: 4413: 4406: 4399: 4379: 4376: 4371: 4368: 4361: 4354: 4351: 4346: 4343: 4336: 4329: 4326: 4321: 4318: 4311: 4304: 4301: 4296: 4293: 4286: 4279: 4276: 4271: 4268: 4246: 4245: 4234: 4229: 4225: 4221: 4218: 4215: 4212: 4209: 4206: 4203: 4200: 4197: 4194: 4191: 4188: 4183: 4179: 4175: 4170: 4166: 4162: 4157: 4153: 4149: 4146: 4141: 4137: 4133: 4130: 4127: 4124: 4121: 4118: 4115: 4112: 4109: 4106: 4101: 4097: 4093: 4088: 4084: 4080: 4075: 4071: 4067: 4064: 4059: 4055: 4051: 4048: 4045: 4042: 4039: 4036: 4033: 4030: 4027: 4024: 4019: 4015: 4011: 4006: 4002: 3998: 3993: 3989: 3985: 3982: 3979: 3976: 3973: 3970: 3967: 3964: 3870:law of cosines 3853: 3850: 3813: 3812: 3801: 3797: 3794: 3791: 3787: 3783: 3778: 3774: 3770: 3765: 3761: 3757: 3752: 3747: 3632: 3631: 3619: 3615: 3612: 3608: 3604: 3600: 3596: 3593: 3589: 3585: 3581: 3577: 3574: 3570: 3566: 3562: 3558: 3555: 3551: 3547: 3543: 3539: 3536: 3532: 3528: 3524: 3520: 3517: 3513: 3492: 3491: 3479: 3474: 3470: 3466: 3461: 3457: 3453: 3448: 3444: 3440: 3435: 3431: 3427: 3422: 3418: 3414: 3409: 3405: 3401: 3396: 3391: 3387: 3383: 3378: 3373: 3369: 3365: 3360: 3355: 3304: 3303: 3292: 3289: 3285: 3281: 3277: 3273: 3269: 3265: 3262: 3258: 3254: 3250: 3245: 3241: 3237: 3232: 3228: 3224: 3219: 3215: 3211: 3206: 3202: 3198: 3193: 3189: 3185: 3180: 3176: 3172: 3167: 3162: 3158: 3154: 3149: 3144: 3140: 3136: 3131: 3126: 3097: 3096: 3081: 3077: 3074: 3071: 3067: 3063: 3058: 3054: 3050: 3045: 3041: 3037: 3034: 3031: 3027: 3023: 3019: 3014: 3010: 3006: 3002: 2998: 2995: 2991: 2988: 2985: 2981: 2978: 2976: 2973: 2968: 2963: 2959: 2958: 2955: 2951: 2948: 2945: 2941: 2937: 2932: 2928: 2924: 2919: 2915: 2911: 2908: 2905: 2901: 2897: 2893: 2888: 2884: 2880: 2876: 2872: 2869: 2865: 2862: 2859: 2855: 2852: 2850: 2847: 2842: 2837: 2833: 2832: 2829: 2825: 2822: 2819: 2815: 2811: 2806: 2802: 2798: 2793: 2789: 2785: 2782: 2779: 2775: 2771: 2767: 2762: 2758: 2754: 2750: 2746: 2743: 2739: 2736: 2733: 2729: 2726: 2724: 2721: 2716: 2711: 2707: 2706: 2631: 2627: 2624: 2615: 2610: 2606: 2603: 2594: 2589: 2585: 2582: 2573: 2568: 2564: 2561: 2542: 2539: 2525: 2501: 2498: 2495: 2492: 2489: 2486: 2481: 2477: 2473: 2470: 2450: 2446: 2443: 2439: 2436: 2433: 2430: 2425: 2421: 2417: 2414: 2394: 2391: 2388: 2385: 2382: 2379: 2375: 2372: 2368: 2365: 2345: 2342: 2338: 2335: 2306: 2303: 2300: 2297: 2294: 2291: 2287: 2283: 2280: 2276: 2272: 2269: 2264: 2260: 2256: 2253: 2219: 2215: 2211: 2208: 2188: 2184: 2180: 2177: 2173: 2169: 2164: 2160: 2156: 2153: 2137: 2131: 2118: 2109: 2088: 2054: 2045: 2032: 2015: 2004: 2003: 1991: 1987: 1984: 1980: 1976: 1972: 1968: 1965: 1961: 1957: 1953: 1949: 1946: 1942: 1938: 1934: 1930: 1927: 1923: 1919: 1915: 1911: 1908: 1904: 1900: 1896: 1892: 1889: 1885: 1881: 1878: 1875: 1872: 1869: 1786: 1783: 1780: 1760: 1757: 1754: 1751: 1748: 1745: 1742: 1739: 1736: 1708: 1705: 1702: 1699: 1696: 1693: 1690: 1687: 1684: 1664: 1660: 1657: 1653: 1650: 1647: 1644: 1641: 1638: 1635: 1615: 1612: 1609: 1606: 1603: 1600: 1596: 1593: 1589: 1586: 1566: 1563: 1559: 1556: 1527: 1524: 1521: 1518: 1515: 1512: 1509: 1506: 1486: 1483: 1480: 1477: 1474: 1471: 1468: 1465: 1462: 1442: 1439: 1436: 1433: 1430: 1427: 1423: 1419: 1416: 1412: 1408: 1404: 1400: 1397: 1393: 1356: 1352: 1349: 1345: 1341: 1337: 1333: 1330: 1326: 1322: 1318: 1314: 1311: 1307: 1303: 1300: 1297: 1294: 1291: 1212: 1209: 1206: 1203: 1200: 1197: 1194: 1190: 1187: 1183: 1180: 1129: 1126: 1123: 1120: 1117: 1114: 1110: 1107: 1103: 1100: 1072: 1069: 1066: 1063: 1060: 1057: 1054: 1051: 1048: 1045: 1042: 1038: 1035: 1031: 1028: 1008: 1005: 1001: 998: 958: 957: 946: 942: 938: 935: 931: 927: 923: 919: 916: 912: 908: 904: 900: 897: 893: 889: 885: 881: 878: 874: 870: 866: 862: 859: 855: 851: 847: 843: 840: 836: 832: 828: 824: 821: 817: 813: 809: 805: 802: 798: 794: 790: 786: 783: 779: 775: 771: 767: 764: 760: 756: 741: 693: 688: 684: 680: 677: 657: 654: 651: 648: 645: 642: 637: 633: 629: 626: 613: 597: 593: 589: 586: 582: 578: 574: 570: 567: 563: 559: 555: 551: 548: 544: 540: 537: 534: 531: 528: 497: 494: 492: 489: 286:. Therefore, 267:. Similarly, 182:The triangles 134: 131: 124: 123: 120: 117: 106: 105: 102: 95: 75: 72: 15: 9: 6: 4: 3: 2: 6225: 6214: 6211: 6210: 6208: 6192: 6191: 6187: 6184: 6183: 6179: 6177: 6174: 6172: 6169: 6167: 6164: 6162: 6159: 6158: 6156: 6152: 6146: 6143: 6141: 6138: 6136: 6133: 6131: 6128: 6126: 6123: 6121: 6118: 6116: 6113: 6111: 6108: 6106: 6103: 6101: 6100:Fermat number 6098: 6096: 6093: 6092: 6090: 6086: 6082: 6075: 6070: 6068: 6063: 6061: 6056: 6055: 6052: 6046: 6043: 6040: 6036: 6033: 6030: 6026: 6025: 6021: 6017: 6013: 6012: 6007: 6003: 6002: 5988: 5987: 5982: 5979: 5972: 5966: 5962: 5956: 5948: 5941: 5935: 5931: 5928: 5922: 5916: 5912: 5909: 5903: 5897: 5893: 5890: 5884: 5878: 5874: 5871: 5865: 5852: 5848: 5844: 5840: 5836: 5832: 5828: 5824: 5820: 5814: 5808: 5803: 5799: 5789: 5788:Weber problem 5786: 5784: 5781: 5779: 5776: 5774: 5771: 5768: 5765: 5764: 5758: 5756: 5746: 5744: 5740: 5736: 5732: 5728: 5724: 5720: 5716: 5713: 5700: 5696: 5693: 5689: 5685: 5681: 5677: 5674: 5673:Lester circle 5670: 5666: 5662: 5658: 5654: 5651: 5647: 5643: 5639: 5635: 5631: 5627: 5622: 5618: 5615: 5611: 5608: 5605: 5601: 5598: 5594: 5591: 5587: 5584: 5580: 5577: 5576: 5574: 5573: 5556: 5552: 5545: 5542: 5536: 5533: 5529: 5525: 5522: 5519: 5515: 5508: 5505: 5499: 5496: 5492: 5488: 5485: 5482: 5478: 5471: 5468: 5462: 5459: 5455: 5451: 5448: 5441: 5440: 5439: 5438: 5434: 5430: 5426: 5422: 5421: 5404: 5400: 5393: 5390: 5384: 5381: 5377: 5373: 5370: 5367: 5363: 5356: 5353: 5347: 5344: 5340: 5336: 5333: 5330: 5326: 5319: 5316: 5310: 5307: 5303: 5299: 5296: 5289: 5288: 5287: 5286: 5282: 5278: 5274: 5270: 5269: 5263: 5260:< 120°), ( 5259: 5256:< 120°), ( 5255: 5250: 5242: 5225: 5218: 5215: 5209: 5206: 5202: 5198: 5195: 5192: 5189: 5186: 5183: 5180: 5177: 5174: 5171: 5167: 5160: 5157: 5151: 5148: 5144: 5140: 5137: 5134: 5131: 5128: 5125: 5122: 5119: 5116: 5113: 5109: 5102: 5099: 5093: 5090: 5086: 5082: 5079: 5076: 5073: 5070: 5067: 5064: 5061: 5058: 5051: 5050: 5049: 5048: 5044: 5043: 5022: 5018: 5011: 5008: 5002: 4999: 4995: 4991: 4988: 4985: 4981: 4974: 4971: 4965: 4962: 4958: 4954: 4951: 4948: 4944: 4937: 4934: 4928: 4925: 4921: 4917: 4914: 4911: 4909: 4900: 4893: 4890: 4884: 4881: 4877: 4873: 4870: 4867: 4863: 4856: 4853: 4847: 4844: 4840: 4836: 4833: 4830: 4826: 4819: 4816: 4810: 4807: 4803: 4799: 4796: 4784: 4783: 4782: 4781: 4777: 4773: 4772: 4751: 4747: 4740: 4737: 4731: 4728: 4724: 4720: 4717: 4714: 4710: 4703: 4700: 4694: 4691: 4687: 4683: 4680: 4677: 4673: 4666: 4663: 4657: 4654: 4650: 4646: 4643: 4640: 4638: 4629: 4622: 4619: 4613: 4610: 4606: 4602: 4599: 4596: 4592: 4585: 4582: 4576: 4573: 4569: 4565: 4562: 4559: 4555: 4548: 4545: 4539: 4536: 4532: 4528: 4525: 4513: 4512: 4511: 4510: 4506: 4502: 4499: 4496: 4492: 4491:circumcircles 4488: 4485: 4481: 4478: 4474: 4473: 4469: 4464: 4455: 4451: 4447: 4441: 4437: 4433: 4426: 4422: 4412: 4405: 4398: 4377: 4369: 4359: 4352: 4344: 4334: 4327: 4319: 4309: 4302: 4294: 4284: 4277: 4269: 4253: 4227: 4223: 4219: 4213: 4210: 4207: 4201: 4198: 4195: 4192: 4189: 4186: 4181: 4177: 4173: 4168: 4164: 4155: 4151: 4147: 4139: 4135: 4131: 4125: 4119: 4116: 4113: 4110: 4107: 4104: 4099: 4095: 4091: 4086: 4082: 4073: 4069: 4065: 4057: 4053: 4049: 4043: 4037: 4034: 4031: 4028: 4025: 4022: 4017: 4013: 4009: 4004: 4000: 3991: 3987: 3983: 3980: 3977: 3974: 3971: 3968: 3965: 3962: 3955: 3954: 3953: 3946: 3942: 3935: 3929: 3919: 3913: 3903: 3897: 3887: 3883: 3879: 3873: 3871: 3867: 3863: 3859: 3849: 3846: 3831: 3827: 3823: 3819: 3799: 3792: 3785: 3772: 3759: 3737: 3736: 3735: 3732: 3725: 3721: 3713: 3705: 3701: 3686: 3682: 3678: 3672: 3668: 3664: 3653: 3646: 3643: 3613: 3610: 3602: 3594: 3591: 3583: 3575: 3572: 3564: 3556: 3553: 3545: 3537: 3534: 3526: 3518: 3515: 3503: 3502: 3501: 3498: 3468: 3455: 3442: 3429: 3416: 3403: 3385: 3367: 3345: 3344: 3343: 3340: 3336: 3332: 3328: 3318: 3314: 3310: 3290: 3279: 3271: 3260: 3252: 3239: 3226: 3213: 3200: 3187: 3174: 3156: 3138: 3116: 3115: 3114: 3111: 3107: 3103: 3079: 3072: 3065: 3052: 3039: 3032: 3025: 3017: 3004: 2993: 2986: 2979: 2977: 2953: 2946: 2939: 2926: 2913: 2906: 2899: 2891: 2878: 2867: 2860: 2853: 2851: 2827: 2820: 2813: 2800: 2787: 2780: 2773: 2765: 2752: 2741: 2734: 2727: 2725: 2697: 2696: 2695: 2692: 2688: 2684: 2674: 2670: 2666: 2660: 2656: 2652: 2648: 2629: 2625: 2622: 2613: 2608: 2604: 2601: 2592: 2587: 2583: 2580: 2571: 2566: 2562: 2559: 2547:O, A, B, C, X 2538: 2536: 2524: 2520:. That means 2496: 2490: 2487: 2479: 2475: 2468: 2444: 2441: 2434: 2431: 2423: 2419: 2412: 2389: 2383: 2380: 2373: 2370: 2363: 2340: 2336: 2333: 2304: 2298: 2292: 2289: 2281: 2278: 2270: 2262: 2258: 2251: 2240:won't lie on 2217: 2213: 2209: 2206: 2199:Moreover, if 2186: 2178: 2175: 2167: 2162: 2158: 2151: 2142: 2136: 2130: 2117: 2113:lies between 2108: 2101: 2087: 2077: 2070: 2063: 2053: 2044: 2031: 2014: 1985: 1982: 1974: 1966: 1963: 1955: 1947: 1944: 1936: 1928: 1925: 1917: 1909: 1906: 1898: 1890: 1887: 1879: 1873: 1867: 1860: 1859: 1858: 1851: 1844: 1837: 1822: 1815: 1814: 1810: 1808: 1784: 1781: 1778: 1755: 1749: 1746: 1740: 1734: 1703: 1697: 1694: 1688: 1682: 1658: 1655: 1648: 1645: 1639: 1633: 1610: 1604: 1601: 1594: 1591: 1584: 1561: 1557: 1554: 1525: 1522: 1519: 1516: 1513: 1507: 1504: 1481: 1475: 1472: 1466: 1460: 1440: 1434: 1428: 1425: 1417: 1414: 1406: 1398: 1395: 1381: 1350: 1347: 1339: 1331: 1328: 1320: 1312: 1309: 1301: 1295: 1289: 1276: 1269: 1262: 1239: 1228: 1227: 1223: 1210: 1204: 1198: 1195: 1188: 1185: 1178: 1171: 1124: 1118: 1115: 1108: 1105: 1098: 1067: 1061: 1058: 1052: 1046: 1043: 1036: 1033: 1026: 1006: 1003: 999: 996: 944: 936: 933: 925: 917: 914: 906: 898: 895: 887: 879: 876: 868: 860: 857: 849: 841: 838: 830: 822: 819: 811: 803: 800: 792: 784: 781: 773: 765: 762: 754: 742: 739: 719: 718: 717: 713: 691: 686: 682: 678: 675: 652: 646: 643: 635: 631: 624: 612: 595: 587: 584: 576: 568: 565: 557: 549: 546: 538: 532: 526: 513: 502: 488: 486: 475: 468: 447: 438:. Therefore, 436: 432: 428: 416: 412: 408: 400: 396: 381: 369: 362: 361: 357: 337: 333: 325: 321: 309: 301: 298:. Using the 295: 291: 283: 276: 272: 266: 263:, using the 260: 252: 246: 240: 233:, the points 226: 221: 217: 210: 206: 196: 191: 187: 180: 170: 165: 158: 154: 150: 139: 130: 127: 121: 118: 115: 111: 110: 109: 103: 100: 96: 93: 90:Construct an 89: 88: 87: 85: 81: 71: 69: 65: 60: 58: 54: 50: 46: 42: 38: 34: 30: 21: 6188: 6180: 6176:Fermat Prize 6125:Fermat point 6124: 6024:Fermat Point 6022: 6009: 5984: 5971: 5960: 5955: 5940: 5921: 5902: 5883: 5864: 5826: 5822: 5813: 5802: 5752: 5742: 5739:Fermat point 5738: 5734: 5730: 5726: 5722: 5718: 5714: 5711: 5709: 5691: 5687: 5683: 5679: 5665:circumcenter 5660: 5656: 5649: 5641: 5637: 5633: 5629: 5620: 5613: 5603: 5596: 5589: 5582: 5432: 5427:(14) is the 5424: 5280: 5275:(13) is the 5272: 5261: 5257: 5253: 4775: 4504: 4494: 4483: 4476: 4449: 4445: 4439: 4435: 4431: 4424: 4420: 4410: 4403: 4396: 4254: 4247: 3944: 3940: 3933: 3927: 3917: 3911: 3901: 3895: 3885: 3881: 3877: 3874: 3855: 3844: 3829: 3825: 3821: 3817: 3814: 3730: 3723: 3719: 3711: 3707:. Note that 3703: 3699: 3689:and placing 3684: 3680: 3676: 3670: 3666: 3662: 3651: 3647: 3641: 3633: 3496: 3493: 3338: 3334: 3330: 3326: 3316: 3312: 3308: 3305: 3109: 3105: 3101: 3098: 2690: 2686: 2682: 2672: 2668: 2664: 2658: 2654: 2650: 2646: 2544: 2534: 2522: 2244:which means 2232:then either 2140: 2134: 2128: 2126:which means 2115: 2106: 2099: 2085: 2075: 2068: 2065:. Moreover, 2061: 2058:lies inside 2051: 2042: 2029: 2012: 2005: 1849: 1842: 1835: 1820: 1816: 1812: 1811: 1806: 1379: 1274: 1267: 1260: 1237: 1229: 1225: 1224: 1153: 1091:-zone, then 959: 714: 610: 511: 507: 473: 466: 448: 434: 430: 426: 419:which means 414: 410: 406: 398: 394: 379: 367: 363: 340:, the point 335: 331: 323: 319: 293: 289: 281: 277: 270: 258: 250: 247: 219: 215: 208: 204: 189: 185: 181: 163: 156: 152: 148: 144: 128: 125: 107: 83: 79: 77: 74:Construction 61: 44: 40: 33:Fermat point 32: 26: 5655:The points 1453:Therefore, 972:itself and 5794:References 5667:, and the 5663:(14), the 5646:Euler line 5628:The lines 5264:< 120°) 4458:Properties 4438:) = − sin 3715:| ≤ 1 3634:and hence 2317:Now allow 1538:Now allow 617:such that 356:concurrent 352:RC, BQ, AP 328:. Because 173:RC, BQ, AP 6016:EMS Press 5986:MathWorld 5859:, p. 174. 5717:(13) and 5678:The line 5671:lie on a 5636:(15) and 5543:π 5537:− 5526:⁡ 5506:π 5500:− 5489:⁡ 5469:π 5463:− 5452:⁡ 5391:π 5374:⁡ 5354:π 5337:⁡ 5317:π 5300:⁡ 5216:π 5210:− 5199:⁡ 5178:− 5158:π 5152:− 5141:⁡ 5120:− 5100:π 5094:− 5083:⁡ 5062:− 5009:π 4992:⁡ 4972:π 4955:⁡ 4935:π 4918:⁡ 4891:π 4885:− 4874:⁡ 4854:π 4848:− 4837:⁡ 4817:π 4811:− 4800:⁡ 4738:π 4732:− 4721:⁡ 4701:π 4695:− 4684:⁡ 4664:π 4658:− 4647:⁡ 4620:π 4603:⁡ 4583:π 4566:⁡ 4546:π 4529:⁡ 4378:β 4375:∂ 4367:∂ 4353:α 4350:∂ 4342:∂ 4325:∂ 4317:∂ 4300:∂ 4292:∂ 4275:∂ 4267:∂ 4220:− 4214:β 4208:α 4202:⁡ 4187:− 4152:λ 4132:− 4126:β 4120:⁡ 4105:− 4070:λ 4050:− 4044:α 4038:⁡ 4023:− 3988:λ 3793:⋅ 3773:− 3760:≤ 3654:> 120° 3565:≤ 3469:− 3443:− 3417:− 3404:≤ 3261:⋅ 3240:− 3214:− 3188:− 3175:≤ 3073:⋅ 3053:− 3040:≤ 3033:⋅ 3018:⋅ 3005:− 2987:⋅ 2947:⋅ 2927:− 2914:≤ 2907:⋅ 2892:⋅ 2879:− 2861:⋅ 2821:⋅ 2801:− 2788:≤ 2781:⋅ 2766:⋅ 2753:− 2735:⋅ 2630:→ 2609:→ 2588:→ 2567:→ 2432:≤ 2344:Ω 2341:∈ 2210:≠ 1782:≠ 1646:≤ 1565:Ω 1562:∈ 1520:≠ 1511:Δ 1508:∈ 1170:such that 888:≥ 751:perimeter 679:≠ 433:= 60° = ∠ 370:> 120° 239:concyclic 195:congruent 6207:Category 5930:Archived 5911:Archived 5892:Archived 5873:Archived 5761:See also 5741:and the 5733:and the 5725:and the 5690:(2) and 3868:and the 3858:vertices 3697:so that 3494:for all 3320:meet at 2516:outside 2512:for all 2445:′ 2374:′ 2337:′ 2096:. Since 1771:for all 1723:outside 1719:for all 1659:′ 1595:′ 1558:′ 1497:for all 1249:(except 1189:′ 1158:outside 1109:′ 1037:′ 1019:implies 1000:′ 668:for all 442:lies on 372:, point 201:. Hence 37:triangle 6154:Related 6018:, 2001 5851:1573021 5843:2690608 5749:History 5706:Aliases 5245:u, v, w 4250:a, b, c 3891:x, y, z 3113:gives 3099:Adding 2405:and as 1839:. Then 1727:. Thus 1626:and as 5849:  5841:  5659:(13), 5243:where 4452:= 120° 4423:= sin 4248:where 3709:| 3660:where 3342:, so 2680:along 2617:  2596:  2575:  2079:about 2010:. Let 1853:about 1824:, let 1278:about 1140:where 417:= 120° 403:hence 360:Q.E.D. 338:= 180° 296:= 180° 284:= 120° 273:= 120° 261:= 120° 99:vertex 53:Fermat 31:, the 5855:See X 5839:JSTOR 5652:(30). 5435:(16): 5283:(15): 4778:(14): 4507:(13): 4497:(13). 3679:= − ( 2102:= 60° 2083:, so 1372:. As 1152:. So 401:= 60° 354:are 326:= 60° 255:, so 253:= 60° 84:X(13) 35:of a 6088:Work 5710:The 5694:(4). 5682:(13) 5640:(14) 5632:(13) 5623:(16) 5616:(15) 5606:(16) 5599:(15) 5592:(14) 5585:(13) 4489:The 4430:sin( 4428:and 4419:sin 3939:π − 3931:and 3915:and 3899:and 2545:Let 2488:< 2381:< 2290:< 2122:and 2023:and 2008:APQD 1857:so 1747:< 1695:< 1602:< 1473:< 1370:CPQF 1196:< 1148:and 1116:< 1059:< 984:and 960:Let 755:> 644:< 519:let 421:BPCF 387:and 368:BAC 304:BPCF 243:AFCQ 237:are 235:ARBF 212:and 193:are 66:and 6037:at 5831:doi 5612:of 5581:of 5523:sin 5486:sin 5449:sin 5371:sin 5334:sin 5297:sin 5196:sec 5138:sec 5080:sec 4989:sec 4952:sec 4915:sec 4871:csc 4834:csc 4797:csc 4718:sec 4681:sec 4644:sec 4600:csc 4563:csc 4526:csc 4443:so 4199:cos 4117:cos 4035:cos 3937:is 3921:be 3905:be 3845:ABC 3727:is 3693:at 3645:. 3642:ABC 3306:If 2644:by 2236:or 2100:CDB 2076:BDA 2069:BCF 2062:ABC 1850:CPB 1843:CQD 1836:CPQ 1821:BCD 1380:ABC 1275:AFQ 1268:ABP 1261:AQP 1245:in 1238:AFB 1166:in 720:If 512:ABC 474:AQC 467:ARB 435:BFA 431:BCP 429:= ∠ 427:BFP 415:AFC 413:+ ∠ 411:AFB 409:= ∠ 407:BFC 399:AFC 397:= ∠ 395:AFB 380:BPC 336:BFA 334:+ ∠ 332:BFP 324:BCP 322:= ∠ 320:BFP 294:BPC 292:+ ∠ 290:BFC 282:BFC 278:So 271:AFC 259:AFB 251:ARB 220:ACF 218:= ∠ 216:AQF 209:ABF 207:= ∠ 205:ARF 190:BAQ 188:, △ 186:RAC 164:ABC 157:CPB 155:, △ 153:AQC 151:, △ 149:ARB 82:or 43:or 27:In 6209:: 6014:, 6008:, 5983:. 5857:13 5847:MR 5845:. 5837:. 5827:67 5825:. 5431:, 5279:, 4448:= 4434:+ 4409:, 4402:, 3943:− 3909:, 3884:, 3880:, 3872:. 3848:. 3828:= 3824:+ 3820:+ 3722:, 3702:= 3683:+ 3669:, 3665:, 3337:= 3333:+ 3329:+ 3315:, 3311:, 3108:, 3104:, 2694:. 2689:, 2685:, 2671:, 2667:, 2657:, 2653:, 2649:, 2537:. 2242:AD 2129:AP 2094:AD 2025:CF 2021:AD 1809:. 1164:P' 1150:BC 1146:AP 1142:P' 729:AC 723:AB 712:. 487:. 480:AP 460:CR 458:, 456:BQ 454:, 452:AP 446:. 444:FP 347:AP 316:, 313:BP 275:. 230:AF 6073:e 6066:t 6059:v 6031:. 5989:. 5949:. 5853:. 5833:: 5719:X 5715:X 5692:X 5688:X 5684:X 5680:X 5675:. 5661:X 5657:X 5650:X 5642:X 5638:X 5634:X 5630:X 5621:X 5614:X 5604:X 5597:X 5590:X 5583:X 5557:. 5553:) 5546:3 5534:C 5530:( 5520:: 5516:) 5509:3 5497:B 5493:( 5483:: 5479:) 5472:3 5460:A 5456:( 5433:X 5425:X 5405:. 5401:) 5394:3 5385:+ 5382:C 5378:( 5368:: 5364:) 5357:3 5348:+ 5345:B 5341:( 5331:: 5327:) 5320:3 5311:+ 5308:A 5304:( 5281:X 5273:X 5266:. 5262:C 5258:B 5254:A 5252:( 5226:) 5219:6 5207:C 5203:( 5193:w 5190:v 5187:u 5184:+ 5181:w 5175:1 5172:: 5168:) 5161:6 5149:B 5145:( 5135:w 5132:v 5129:u 5126:+ 5123:v 5117:1 5114:: 5110:) 5103:6 5091:A 5087:( 5077:w 5074:v 5071:u 5068:+ 5065:u 5059:1 5023:. 5019:) 5012:6 5003:+ 5000:C 4996:( 4986:: 4982:) 4975:6 4966:+ 4963:B 4959:( 4949:: 4945:) 4938:6 4929:+ 4926:A 4922:( 4912:= 4901:) 4894:3 4882:C 4878:( 4868:: 4864:) 4857:3 4845:B 4841:( 4831:: 4827:) 4820:3 4808:A 4804:( 4776:X 4752:. 4748:) 4741:6 4729:C 4725:( 4715:: 4711:) 4704:6 4692:B 4688:( 4678:: 4674:) 4667:6 4655:A 4651:( 4641:= 4630:) 4623:3 4614:+ 4611:C 4607:( 4597:: 4593:) 4586:3 4577:+ 4574:B 4570:( 4560:: 4556:) 4549:3 4540:+ 4537:A 4533:( 4505:X 4495:X 4484:X 4477:X 4450:β 4446:α 4440:β 4436:β 4432:α 4425:β 4421:α 4414:3 4411:λ 4407:2 4404:λ 4400:1 4397:λ 4370:L 4360:, 4345:L 4335:, 4328:z 4320:L 4310:, 4303:y 4295:L 4285:, 4278:x 4270:L 4233:) 4228:2 4224:c 4217:) 4211:+ 4205:( 4196:x 4193:z 4190:2 4182:2 4178:x 4174:+ 4169:2 4165:z 4161:( 4156:3 4148:+ 4145:) 4140:2 4136:b 4129:) 4123:( 4114:z 4111:y 4108:2 4100:2 4096:z 4092:+ 4087:2 4083:y 4079:( 4074:2 4066:+ 4063:) 4058:2 4054:a 4047:) 4041:( 4032:y 4029:x 4026:2 4018:2 4014:y 4010:+ 4005:2 4001:x 3997:( 3992:1 3984:+ 3981:z 3978:+ 3975:y 3972:+ 3969:x 3966:= 3963:L 3950:L 3945:β 3941:α 3934:Z 3928:X 3923:β 3918:Z 3912:Y 3907:α 3902:Y 3896:X 3886:Z 3882:Y 3878:X 3843:△ 3839:C 3835:O 3830:0 3826:k 3822:j 3818:i 3800:, 3796:k 3790:x 3786:+ 3782:| 3777:x 3769:0 3764:| 3756:| 3751:0 3746:| 3731:C 3729:∠ 3724:j 3720:i 3712:k 3704:0 3700:c 3695:C 3691:O 3687:) 3685:j 3681:i 3677:k 3671:c 3667:b 3663:a 3658:O 3652:C 3650:∠ 3640:△ 3636:O 3618:| 3614:C 3611:X 3607:| 3603:+ 3599:| 3595:B 3592:X 3588:| 3584:+ 3580:| 3576:A 3573:X 3569:| 3561:| 3557:C 3554:O 3550:| 3546:+ 3542:| 3538:B 3535:O 3531:| 3527:+ 3523:| 3519:A 3516:O 3512:| 3497:x 3478:| 3473:x 3465:c 3460:| 3456:+ 3452:| 3447:x 3439:b 3434:| 3430:+ 3426:| 3421:x 3413:a 3408:| 3400:| 3395:c 3390:| 3386:+ 3382:| 3377:b 3372:| 3368:+ 3364:| 3359:a 3354:| 3339:0 3335:k 3331:j 3327:i 3322:O 3317:c 3313:b 3309:a 3291:. 3288:) 3284:k 3280:+ 3276:j 3272:+ 3268:i 3264:( 3257:x 3253:+ 3249:| 3244:x 3236:c 3231:| 3227:+ 3223:| 3218:x 3210:b 3205:| 3201:+ 3197:| 3192:x 3184:a 3179:| 3171:| 3166:c 3161:| 3157:+ 3153:| 3148:b 3143:| 3139:+ 3135:| 3130:a 3125:| 3110:c 3106:b 3102:a 3080:. 3076:k 3070:x 3066:+ 3062:| 3057:x 3049:c 3044:| 3036:k 3030:x 3026:+ 3022:k 3013:) 3009:x 3001:c 2997:( 2994:= 2990:k 2984:c 2980:= 2972:| 2967:c 2962:| 2954:, 2950:j 2944:x 2940:+ 2936:| 2931:x 2923:b 2918:| 2910:j 2904:x 2900:+ 2896:j 2887:) 2883:x 2875:b 2871:( 2868:= 2864:j 2858:b 2854:= 2846:| 2841:b 2836:| 2828:, 2824:i 2818:x 2814:+ 2810:| 2805:x 2797:a 2792:| 2784:i 2778:x 2774:+ 2770:i 2761:) 2757:x 2749:a 2745:( 2742:= 2738:i 2732:a 2728:= 2720:| 2715:a 2710:| 2691:c 2687:b 2683:a 2678:O 2673:k 2669:j 2665:i 2659:x 2655:c 2651:b 2647:a 2626:X 2623:O 2614:, 2605:C 2602:O 2593:, 2584:B 2581:O 2572:, 2563:A 2560:O 2531:Δ 2526:0 2523:P 2518:Δ 2514:P 2500:) 2497:P 2494:( 2491:d 2485:) 2480:0 2476:P 2472:( 2469:d 2449:) 2442:P 2438:( 2435:d 2429:) 2424:0 2420:P 2416:( 2413:d 2393:) 2390:P 2387:( 2384:d 2378:) 2371:P 2367:( 2364:d 2334:P 2323:Δ 2319:P 2305:. 2302:) 2299:P 2296:( 2293:d 2286:| 2282:D 2279:A 2275:| 2271:= 2268:) 2263:0 2259:P 2255:( 2252:d 2238:Q 2234:P 2218:0 2214:P 2207:P 2187:. 2183:| 2179:D 2176:A 2172:| 2168:= 2163:0 2159:P 2155:( 2152:d 2141:D 2138:0 2135:Q 2132:0 2124:D 2119:0 2116:P 2110:0 2107:Q 2098:∠ 2089:0 2086:Q 2081:B 2074:△ 2067:△ 2060:△ 2055:0 2052:P 2046:0 2043:Q 2038:P 2033:0 2030:P 2016:0 2013:P 1990:| 1986:D 1983:Q 1979:| 1975:+ 1971:| 1967:Q 1964:P 1960:| 1956:+ 1952:| 1948:P 1945:A 1941:| 1937:= 1933:| 1929:C 1926:P 1922:| 1918:+ 1914:| 1910:B 1907:P 1903:| 1899:+ 1895:| 1891:A 1888:P 1884:| 1880:= 1877:) 1874:P 1871:( 1868:d 1855:C 1848:△ 1841:△ 1834:△ 1830:Δ 1826:P 1819:△ 1803:Δ 1799:A 1785:A 1779:P 1759:) 1756:P 1753:( 1750:d 1744:) 1741:A 1738:( 1735:d 1725:Δ 1721:P 1707:) 1704:P 1701:( 1698:d 1692:) 1689:A 1686:( 1683:d 1663:) 1656:P 1652:( 1649:d 1643:) 1640:A 1637:( 1634:d 1614:) 1611:P 1608:( 1605:d 1599:) 1592:P 1588:( 1585:d 1555:P 1544:Δ 1540:P 1526:. 1523:A 1517:P 1514:, 1505:P 1485:) 1482:P 1479:( 1476:d 1470:) 1467:A 1464:( 1461:d 1441:. 1438:) 1435:A 1432:( 1429:d 1426:= 1422:| 1418:F 1415:A 1411:| 1407:+ 1403:| 1399:C 1396:A 1392:| 1378:△ 1374:P 1355:| 1351:F 1348:Q 1344:| 1340:+ 1336:| 1332:Q 1329:P 1325:| 1321:+ 1317:| 1313:P 1310:C 1306:| 1302:= 1299:) 1296:P 1293:( 1290:d 1280:A 1273:△ 1266:△ 1259:△ 1255:Q 1251:A 1247:Δ 1243:P 1236:△ 1232:A 1211:. 1208:) 1205:P 1202:( 1199:d 1193:) 1186:P 1182:( 1179:d 1168:Ω 1160:Δ 1156:P 1128:) 1125:P 1122:( 1119:d 1113:) 1106:P 1102:( 1099:d 1089:A 1085:P 1071:) 1068:P 1065:( 1062:d 1056:) 1053:A 1050:( 1047:d 1044:= 1041:) 1034:P 1030:( 1027:d 1007:A 1004:= 997:P 986:C 982:B 978:P 974:P 970:Δ 966:Δ 962:P 945:. 941:| 937:C 934:B 930:| 926:+ 922:| 918:C 915:A 911:| 907:+ 903:| 899:B 896:A 892:| 884:| 880:B 877:X 873:| 869:+ 865:| 861:X 858:C 854:| 850:+ 846:| 842:C 839:A 835:| 831:+ 827:| 823:B 820:A 816:| 812:= 808:| 804:B 801:X 797:| 793:+ 789:| 785:X 782:A 778:| 774:+ 770:| 766:B 763:A 759:| 740:: 734:X 710:Ω 706:Δ 692:. 687:0 683:P 676:P 656:) 653:P 650:( 647:d 641:) 636:0 632:P 628:( 625:d 614:0 611:P 596:. 592:| 588:C 585:P 581:| 577:+ 573:| 569:B 566:P 562:| 558:+ 554:| 550:A 547:P 543:| 539:= 536:) 533:P 530:( 527:d 517:P 510:△ 472:△ 465:△ 440:A 425:∠ 405:∠ 393:∠ 389:F 385:A 378:△ 374:A 366:∠ 342:F 330:∠ 318:∠ 288:∠ 280:∠ 269:∠ 257:∠ 249:∠ 214:∠ 203:∠ 199:A 184:△ 177:F 162:△ 147:△

Index


Euclidean geometry
triangle
geometric median
Fermat
Evangelista Torricelli
geometric median
Steiner tree problems
equilateral triangle
vertex
isosceles triangle

concyclic points
congruent
inscribed angle theorem
concyclic
inscribed angle theorem
inscribed angle theorem
inscribed angle theorem
concurrent
Q.E.D.
Napoleon's Theorem

triangle inequality
vertices
mathematical optimization
Lagrange multipliers
law of cosines

vesicae piscis

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