Question

What is the measure of ∠RST? A) 49° B) 52° C) 59° D) 79°

Answer 1

Measure of ∠RST is 49°

Solution:

The image of the question is attached below.

In the given image ∠SRT = 79° and ext∠T = 128°.

∠R and ∠S are opposite interior angles of exterior angle T.

To find the measure of ∠RST.

Exterior angle property:

An exterior angle is equal to the sum of the two opposite interior angles.

⇒ ∠RST + ∠SRT = ∠T

⇒ ∠RST + 79° = 128°

⇒ ∠RST = 128° – 79°

⇒ ∠RST = 49°

Hence the measure of ∠RST is 49°.