Find the measure of angle A

45°

Step-by-step explanation:

The sum of interior angles in a triangle is equal to 180°

60 + x + 87 + x + 57 = 180 add like terms

2x + 204 = 180 subtract 204 from both sides

2x = -24 divide both sides by 2

x = -12

angle A is x + 57 so if we replace A with the value we found

(-12) + 57 = 45°

c. prove the lengths are the same.

step-by-step explanation:

you need to prove the segments are congruent. congruent segments have the same length. find the lengths of the segments using the distance formula, and compare them.

answer: c. prove the lengths are the same.