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°.
