Question

what is the value of d? 30°

Explanation:

Step1: Assume it's a right - angle

Assume the total angle is \(90^{\circ}\) (common in such geometric set - ups if not specified otherwise).

Step2: Calculate \(d\)

Use the formula \(d = 90^{\circ}-30^{\circ}\).

Answer:

\(d = 60^{\circ}\)