Provide the Requested Proof $\mathrm { ABC }$ Be a Triangle, and Let

question 115

Essay

Provide the requested proof.
-Let $\mathrm { ABC }$ be a triangle, and let $\mathrm { M }$ be the midpoint of side $\overline { \mathrm { BC } }$ . If $\overline { \mathrm { AM } }$ is perpendicular to $\overline { \mathrm { BC } }$ , prove that $A B C$ is an isosceles triangle.