Fill in the blanks to complete the proof that m∠1+m∠3+m∠2=180°

Question

given the diagram.

(2 points)
Given the diagram shown, ∠
≅∠5
; ∠2≅∠4
because alternate interior angles are congruent when lines are parallel. Then, I know that m∠1=m∠5
; m∠2=m∠4
because congruent angles have equal measures. m∠
+m∠3+m∠4=180°
by the definition of a straight angle. Finally, m∠1+m∠3+m∠
=180°
by substitution.

Answer 1

m∠1+m∠3+m∠2=180°.