Eric must prove that the base angles of an isosceles triangle are congruent. He draws a line segment that connects the midpoint of the base to the opposite vertex. Which postulate may be used to prove the angle congruence?

5(2a-5+b). xbox xboxxbx xb

1. statement- ca is parallel to db and e is the midpoint of ad reason- given2. statement- reason- alternate interior angles3. statement- de is congruent to ae reason- definition of midpoint4. statement- triangle aec is congruent to triangle deb reason- asa (angle side angle)