Question

find the measure of the missing angle.

Explanation:

Step1: Recall angle - sum property

The two angles \(a\) and \(69^{\circ}\) form a right - angle. A right - angle measures \(90^{\circ}\). So, \(a + 69^{\circ}=90^{\circ}\).

Step2: Solve for \(a\)

We can find \(a\) by subtracting \(69^{\circ}\) from \(90^{\circ}\), i.e., \(a=90^{\circ}-69^{\circ}\).

Answer:

\(21^{\circ}\)