Question

points a, b, and c are on line ac.
angle cbd has a measure of $140^\circ$. what is the measure of angle abd?
$40^\circ$
$50^\circ$
$60^\circ$
$70^\circ$

Explanation:

Step1: Recognize supplementary angles

Points A, B, C are colinear, so $\angle ABD + \angle CBD = 180^\circ$

Step2: Solve for $\angle ABD$

Rearrange to isolate $\angle ABD$: $\angle ABD = 180^\circ - \angle CBD$
Substitute $\angle CBD = 140^\circ$: $\angle ABD = 180^\circ - 140^\circ$

Answer:

$40^\circ$ (Option A)