Question

Two parallel lines are crossed by a transversal.

Horizontal and parallel lines b and c are cut by transversal a. At the intersection of lines b and a, the bottom left angle is (5 x + 5) degrees. At the intersection of lines c and a, the bottom right angle is 115 degrees.
What is the value of x?

x = 12
x = 14
x = 22
x = 24

Answer 1

x = 12

Reason: The bottom-right angle at the lower intersection (115°) is corresponding to the bottom-right angle at the upper intersection, so the upper bottom-right angle is also 115°. At the upper intersection the bottom-left angle and bottom-right angle form a linear pair, so they sum to 180°:
5x + 5 = 180 − 115 = 65 → 5x = 60 → x = 12.