Question

if one angle is 100 degrees, what is the measure of its consecutive interior angle?
a. 60 degrees
b. 120 degrees
c. 80 degrees
d. 90 degrees

Explanation:

Step1: Recall angle - pair property

Consecutive interior angles are supplementary.

Step2: Set up the equation

Let the given angle be $\angle A = 100^{\circ}$ and the consecutive interior angle be $\angle B$. The equation is $\angle A+\angle B = 180^{\circ}$.

Step3: Solve for the unknown angle

$\angle B=180^{\circ}-\angle A$. Substitute $\angle A = 100^{\circ}$ into the equation: $\angle B = 180 - 100=80^{\circ}$.

Answer:

C. 80 degrees