旁心四邊形(英語:Ex-tangential quadrilateral 或 exscriptible quadrilateral)是指四條邊向外延伸英語Extended side後能與一個圓心在四邊形外的圓相切的四邊形[1][2]

  旁心四邊形 ABCD
  ABCD的四條邊延長線英語Extended side
  ABCD旁切圓

參考文獻

編輯
  1. ^ Radic, Mirko; Kaliman, Zoran and Kadum, Vladimir, "A condition that a tangential quadrilateral is also a chordal one", Mathematical Communications, 12 (2007) pp. 33–52.
  2. ^ Bogomolny, Alexander. "Inscriptible and Exscriptible Quadrilaterals", Interactive Mathematics Miscellany and Puzzles. [2011-08-18]. (原始內容存檔於2011-09-06).