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Giovanni Fagnano

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155: 99:, the geometric median is the point where the two diagonals of the quadrilateral cross each other. In the other possible case, not considered by Fagnano, one point lies within the triangle formed by the other three, and this inner point is the geometric median. Thus, in both cases, the geometric median coincides with the 165: 77:, whose vertices are the points where the altitudes of the original triangle cross its sides. Another property of the orthic triangle, also proven by Fagnano, is that its 21: 364: 92:; this is the point minimizing the sum of its distances to the four given points. As Fagnano showed, when the four points form the vertices of a 359: 258: 136: 31: 239: 369: 354: 131: 141: 170: 229: 349: 344: 312:
Fagnano, G. F. (1775), "Problemata quaedam ad methodum maximorum et minimorum spectantia",
214: 59: 285: 8: 259:"Four-point Fermat location problems revisited. New proofs and extensions of old results" 127: 30:, died 14 May 1797 in Senigallia) was an Italian churchman and mathematician, the son of 289: 327: 202: 235: 281: 273: 194: 85: 210: 89: 74: 254: 185:
Gutkin, Eugene (1997), "Two applications of calculus to triangular billiards",
78: 70: 43: 338: 159: 96: 277: 100: 206: 93: 47: 27: 231:
Shortest Connectivity: An Introduction with Applications in Phylogeny
63: 198: 158: This article incorporates text from a publication now in the 66: 234:, Combinatorial Optimization, vol. 17, Springer, p. 6, 84:
Fagnano also partially solved the problem of finding the
328:
http://www.izwtalt.uni-wuppertal.de/Acta/NAE1775.pdf
42:
Fagnano was ordained as a priest. In 1752 he became
125: 336: 81:are the altitudes of the original triangle. 365:18th-century Italian Roman Catholic priests 163: 121: 119: 117: 115: 73:. As Fagnano showed, the solution is the 253: 311: 227: 137:MacTutor History of Mathematics Archive 132:"Giovanni Francesco Fagnano dei Toschi" 112: 337: 184: 62:, the problem of inscribing a minimum- 266:IMA Journal of Management Mathematics 174:. New York: Robert Appleton Company. 360:18th-century Italian mathematicians 37: 13: 166:Giulio Carlo de' Toschi di Fagnano 164:Herbermann, Charles, ed. (1913). " 32:Giulio Carlo de' Toschi di Fagnano 14: 381: 187:The American Mathematical Monthly 147: 153: 50:of the cathedral of Senigallia. 46:, and in 1755 he was appointed 321: 305: 247: 221: 178: 88:of sets of four points in the 53: 1: 106: 7: 10: 386: 103:of the four given points. 228:Cieslik, Dietmar (2006), 26:(born 31 January 1715 in 142:University of St Andrews 34:, also a mathematician. 370:People from Senigallia 355:Italian mathematicians 278:10.1093/imaman/dpl007 171:Catholic Encyclopedia 58:Fagnano is known for 16:Italian mathematician 314:Nova Acta Eruditorum 128:Robertson, Edmund F. 126:O'Connor, John J.; 20:Giovanni Francesco 60:Fagnano's problem 377: 330: 325: 319: 317: 309: 303: 302: 301: 300: 294: 288:, archived from 263: 251: 245: 244: 225: 219: 217: 182: 176: 175: 157: 156: 151: 145: 144: 123: 86:geometric median 38:Religious career 385: 384: 380: 379: 378: 376: 375: 374: 335: 334: 333: 326: 322: 310: 306: 298: 296: 292: 261: 255:Plastria, Frank 252: 248: 242: 226: 222: 199:10.2307/2975055 183: 179: 154: 152: 148: 124: 113: 109: 90:Euclidean plane 79:angle bisectors 75:orthic triangle 56: 40: 17: 12: 11: 5: 383: 373: 372: 367: 362: 357: 352: 347: 332: 331: 320: 304: 272:(4): 387–396, 246: 240: 220: 193:(7): 618–622, 177: 146: 110: 108: 105: 71:acute triangle 55: 52: 39: 36: 15: 9: 6: 4: 3: 2: 382: 371: 368: 366: 363: 361: 358: 356: 353: 351: 348: 346: 343: 342: 340: 329: 324: 315: 308: 295:on 2016-03-04 291: 287: 283: 279: 275: 271: 267: 260: 256: 250: 243: 241:9780387235394 237: 233: 232: 224: 216: 212: 208: 204: 200: 196: 192: 188: 181: 173: 172: 167: 161: 160:public domain 150: 143: 139: 138: 133: 129: 122: 120: 118: 116: 111: 104: 102: 98: 97:quadrilateral 95: 91: 87: 82: 80: 76: 72: 68: 65: 61: 51: 49: 45: 35: 33: 29: 25: 23: 323: 313: 307: 297:, retrieved 290:the original 269: 265: 249: 230: 223: 190: 186: 180: 169: 149: 135: 83: 57: 41: 19: 18: 350:1797 deaths 345:1715 births 101:Radon point 54:Mathematics 339:Categories 299:2014-05-18 286:1126.90046 107:References 69:within an 48:archdeacon 28:Senigallia 24:dei Toschi 316:: 281–303 64:perimeter 257:(2006), 67:triangle 215:1468291 207:2975055 162::  22:Fagnano 284:  238:  213:  205:  94:convex 293:(PDF) 262:(PDF) 203:JSTOR 44:canon 236:ISBN 282:Zbl 274:doi 195:doi 191:104 168:". 341:: 280:, 270:17 268:, 264:, 211:MR 209:, 201:, 189:, 140:, 134:, 130:, 114:^ 318:. 276:: 218:. 197::

Index

Fagnano
Senigallia
Giulio Carlo de' Toschi di Fagnano
canon
archdeacon
Fagnano's problem
perimeter
triangle
acute triangle
orthic triangle
angle bisectors
geometric median
Euclidean plane
convex
quadrilateral
Radon point




Robertson, Edmund F.
"Giovanni Francesco Fagnano dei Toschi"
MacTutor History of Mathematics Archive
University of St Andrews
public domain
Giulio Carlo de' Toschi di Fagnano
Catholic Encyclopedia
doi
10.2307/2975055
JSTOR

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