Question

lines m and n are parallel. find the measure of ∠a. m∠a = ?°

Explanation:

Step1: Identify angle relationship

The 124° angle and ∠a are corresponding angles? No, wait—they form a linear pair with vertical angles? Wait, correct: when parallel lines are cut by a transversal, the angle supplementary to 124° is equal to ∠a (corresponding angles).

Step2: Calculate supplementary angle

Supplementary angle = 180° - 124° = 56°. So ∠a = 56°.

Answer:

56