Answer
20
Explanation
USP is a triangle,
The angle at the center is double the angle at the circumference.
∴ <VSU at the circumference = 80/2 = 40°
< USP = 180 - 40 = 140. (angles in a straight line)
The angle SUT = 20
Angles in a triangle add up to 180.
180 - (140 + 20) = 180 - 160
= 20°
