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