points a, b, and c are on line ac. angle cbd has a measure of 140°. what is the measure of angle abd? 40°…
points a, b, and c are on line ac. angle cbd has a measure of 140°. what is the measure of angle abd? 40° 50° 60° 70°
Answer
Explanation:
Step1: Recall angle - addition postulate
Since points A, B, and C are on line AC, $\angle ABD+\angle CBD = 180^{\circ}$ (linear - pair of angles).
Step2: Solve for $\angle ABD$
Let $\angle ABD=x$. We know that $\angle CBD = 140^{\circ}$. Then $x+140^{\circ}=180^{\circ}$. So $x=180^{\circ}-140^{\circ}$. $x = 40^{\circ}$
Answer:
$40^{\circ}$