Question

question 4 of 10
what is the measure of ∠abc in the figure below?
a. 42°
b. 48°
c. 84°
d. 30°
e. 21°
f. cannot be determined

Explanation:

Step1: Identify given angle

Given $\angle ABD = 42^{\circ}$.

Step2: Analyze the figure

$\angle ABC = 2\angle ABD$ as the line $BD$ is an angle - bisector.

Step3: Calculate $\angle ABC$

$\angle ABC=2\times42^{\circ}=84^{\circ}$

Answer:

C. $84^{\circ}$