Ta chứng minh $\widehat{MAE}+\widehat{FEA}=90^o$Dế thấy: $\widehat{MAE}=\widehat{CBA}$ $\widehat{FEA}=\widehat{FHA}=\widehat{ACB}$
Ta chứng minh $\widehat{MAE}+\widehat{FEA}=90^o$Dế thấy: $\widehat{MAE}=\widehat{BCA}$ $\widehat{FEA}=\widehat{FHA}=\widehat{ABC}$
Ta chứng minh $\widehat{MAE}+\widehat{FEA}=90^o$Dế thấy: $\widehat{MAE}=\widehat{C
BA}$ $\widehat{FEA}=\widehat{FHA}=\widehat{AC
B}$