Write a two-column proof. Given: Triangle ACD is isosceles; <1 is congruent to <3 Prove: Segment AB || Segment CD

The answer is explained below

Step-by-step explanation:

Statement                                                        Reason

Triangle ACD is isosceles and                         Given

<1 = <3 (<1 is congruent to <3)                                                            

∠3 = ∠4                                                             Isosceles   triangle base angles.

∠1 = ∠4                                                              Substitution Theorem

∠1 = ∠4                                                             They are produced by two lines .                                                                         AB and CD cut by transversal  

.                                                                         line AD

Segment AB || Segment CD                           Alternate interior angle theorem  

The Alternate interior angle theorem states that if two lines cut by a transversal line form congruent alternate interior angles, then the two lines are parallel to each other.