翻訳と辞書 Words near each other ・ Crossett Municipal Auditorium ・ Crossett Municipal Building ・ Crossett Post Office ・ Crossett School District ・ Crossett, Arkansas ・ Crosseyed and Painless ・ Crosseyed Heart ・ Crossfade ・ Crossback stingaree ・ Crossband operation ・ Crossbank ・ Crossbar ・ Crossbar (computer hardware manufacturer) ・ Crossbar latch ・ Crossbar switch ・ Crossbar theorem ・ Crossbarry ・ Crossbarry Ambush ・ Crossbeam Systems ・ Crossbelt Mani ・ Crossbencher ・ Crossbill ・ Crossbill Guides Foundation ・ Crossbite ・ Crossbones ・ Crossbones (comics) ・ CrossBones (film) ・ Crossbones (TV series) ・ Crossbost ・ Crossbow Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Crossbar theorem ： ウィキペディア英語版 Crossbar theorem In geometry, the crossbar theorem states that if ray AD is between ray AC and ray AB, then ray AD intersects line segment BC. This result is one of the deeper results in axiomatic plane geometry. It is often used in proofs to justify the statement that a line through a vertex of a triangle lying ''inside'' the triangle meets the side of the triangle opposite that vertex. This property was often used by Euclid in his proofs without explicit justification. Some modern treatments (not Euclid's) of the proof of the theorem that the base angles of an isosceles triangle are congruent start like this: Let ABC be a triangle with side AB congruent to side AC. ''Draw the angle bisector of angle A and let D be the point at which it meets side BC''. And so on. The justification for the existence of point D is the often unstated crossbar theorem. For this particular result, other proofs exist which do not require the use of the crossbar theorem. ==See also== * Foundations of geometry 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Crossbar theorem」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.