Question

1. consider an angle abc, where the measure of angle abc is 90°, measure of angle abd is 30°. what is the measure of angle dbc?

30°
45°
60°
120°

Explanation:

Step1: Identify angle - relationship

We know that $\angle ABC=\angle ABD+\angle DBC$.

Step2: Solve for $\angle DBC$

$\angle DBC=\angle ABC - \angle ABD$. Given $\angle ABC = 90^{\circ}$ and $\angle ABD=30^{\circ}$, then $\angle DBC=90^{\circ}-30^{\circ}=60^{\circ}$.

Answer:

C. $60^{\circ}$