Question

Two parallel lines are crossed by a transversal.

Horizontal and parallel lines e and f are cut by transversal d. At the intersection of lines e and d, the bottom right angle is 78 degrees. At the intersection of lines f and d, the top right angle is m degrees.
What is the value of m?

m = 68
m = 78
m = 102
m = 112

Answer 1

102

Reason: The given angles are same‑side interior (consecutive interior) angles formed by a transversal cutting parallel lines, so they are supplementary: m = 180 − 78 = 102.