Geometry proof question?

proof by contradiction: ume BD is perp to AC. Then BD forms congruent right angles with AC. Since BD is a median, AD congruent to DC. By reflexive property, you have BD cong. BD. So by SAS the triangles ADB and CDB are congruent. CPCTC would mean that AB is Congruent to BC, but that contradicts the given. Hence BD is not perp to AC.