Chen, Zhibo; Liang, Tian (2006). “The converse of Viviani's theorem”. 《The College Mathematics Journal》 37 (5): 390–391. doi:10.2307/27646392. JSTOR27646392.
jstor.org
Chen, Zhibo; Liang, Tian (2006). “The converse of Viviani's theorem”. 《The College Mathematics Journal》 37 (5): 390–391. doi:10.2307/27646392. JSTOR27646392.