L1 is parallel to L2, and therefore ​m∠t=m∠x​ and ​m∠w=m∠y​. Which can be used to show that the sum of the interior angles of the triangle is 180°? Responses A straight angle has a measure of 180°, so ​m∠t+m∠v+m∠w=180°​, and since m∠t=m∠x​ and m∠w=m∠y​, ​m∠x+m∠y+m∠v=180°​. A straight angle has a measure of , so ​m∠t+m∠v+m∠w=180°​, and since m∠t=m∠x​, , and m∠w=m∠y​, ​m∠x+m∠y+m∠v=180°​. Alternate interior angles are equal, so ​m∠t=m∠x​ and ​m∠w=m∠y​, and since ∠x and ∠y​ are supplementary, ​m∠x+m∠y+m∠v=180°.​Alternate interior angles are equal, so ​m∠t=m∠x​, , and ​m∠w=m∠y​, and since ∠x and ∠y​, , are supplementary, ​m∠x+m∠y+m∠v=180°.​ Since ​m∠t=m∠x​ and ​m∠w=m∠y​, and m∠v=90°​, the sum of the angles is ​m∠x+m∠y+m∠v=180°.​Since ​m∠t=m∠x​ and ​m∠w=m∠y​, and m∠v=90°​, the sum of the angles is ​m∠x+m∠y+m∠v=180°.​ The interior angles of a triangle are complementary, so since ​m∠t=m∠x​ and ​m∠w=m∠y​, ​m∠x+m∠y+m∠v=180°​. The interior angles of a triangle are complementary, so since ​m∠t=m∠x​, , and ​m∠w=m∠y​, ​m∠x+m∠y+m∠v=180°​.