Question

mình cần lời giải chi tiết chính sát mình cảm ơn

Answer 1

\(a,\left\{{}\begin{matrix}AB=AC\\BM=MC\\AM\text{ chung}\end{matrix}\right.\Rightarrow\Delta AMB=\Delta AMC\left(c.c.c\right)\\ b,\Delta AMB=\Delta AMC\\ \Rightarrow\widehat{AMB}=\widehat{AMC}\\ \text{Mà }\widehat{AMB}+\widehat{AMC}=180^0\left(\text{kề bù}\right)\\ \Rightarrow\widehat{AMB}=\widehat{AMC}=90^0\\ \Rightarrow AM\perp BC\)