Question

find the measure of angle x,
given a || b.

x = ?°

Explanation:

Step1: Find the angle adjacent to \(159^{\circ}\)

Since the sum of adjacent angles on a straight line is \(180^{\circ}\), the adjacent angle to \(159^{\circ}\) is \(180^{\circ}- 159^{\circ}=21^{\circ}\).

Step2: Use the property of parallel lines

When \(a\parallel b\), the alternate - interior angles are equal. The angle \(x\) is composed of two angles. One is the \(21^{\circ}\) angle (from step 1) and the other \(21^{\circ}\) angle (given). So \(x = 21^{\circ}+21^{\circ}\).

Answer:

\(42\)