Option B:
25 degrees
Solution:
Given data in triangle PQR,
The side opposite to angle P is p.
The side opposite to angle Q is q.
The side opposite to angle R is r.
q = 36, r = 20, angle Q = 50°.
<u>To find the measure of angle R:</u>
Using law of sine,


Take only two sides.

Substitute the given values.

Do cross multiplication.

sin 50° = 0.766





⇒ R = 25.18°
⇒ R = 25° (approximately)
Option B is the correct answer.
Hence the measure of angle R is 25 degrees.