Question

Please help!

Answer 1

I constructed line AD as a perpendicular bisector of line BC. Angles BDA and CDA are both 90 degrees because of the construction of a perpendicular bisector. Angles BDA and CDA are congruent because of the transitive property of equality.  Line BD is also equal to CD according to the definition of a perpendicular bisector. Triangles ABD and ACD are congruent by the angle side angle postulate. Since the parts of the congruent triangles are congruent, lines AB and AC are congruent.