Question

question find the measure of the missing angle.

Explanation:

Step1: Recall angle - sum property

The two angles are supplementary, meaning their sum is 180°. Let the missing angle be \(a\). So, \(a + 129^{\circ}=180^{\circ}\).

Step2: Solve for the missing angle

Subtract 129° from both sides of the equation: \(a=180^{\circ}- 129^{\circ}\).
\(a = 51^{\circ}\)

Answer:

\(51^{\circ}\)