Two supporting reasons are missing from the proof. Complete the proof by dragging and dropping the appropriate reasons into each of the empty boxes.
Given: m∥nm∠1=120°

Prove: m∠6=60°

The figure shows what appear to be parallel lines n and m rising from left to right with line m above line n. Line p rises slightly from left to right first intersecting line n, then line m. The angles formed by the intersection of lines p and m are numbered from 1 through 4 in a clockwise direction starting with angle 1 which is located above line m and to the left of line p. The angles formed by the intersection of lines p and n are numbered 5 through 8 in a clockwise direction with angle 5 above line n and to the left of line p.

Statements Reasons
​ m∥nm∠1=120° ​ Given
∠5≅∠1
m∠5=m∠1 Angle Congruence Postulate
m∠5=120° Substitution Property of Equality
m∠6+m∠5=180°
m∠6+120°=180° Substitution Property of Equality
m∠6=60° ​ Subtraction Property of Equality


Linear Pair PostulateAlternate Interior Angles TheoremSubstitution Property of EqualityCorresponding Angles Postulate