Chapter 12.1, Problem 6MC

To determine

To write:

An argument that prove the following theorem,

“For every isosceles triangle,

a. The angles opposite the congruent sides are congruent (base angles of an isoscelestriangle are congruent);

b. The angle bisector of an angle formed by two congruent sides lies on the perpendicular bisector of the thrid side of the triangle”