Answer:
Step-by-step explanation:
Side PQ is a chord through the center and angle R is a right angle. This means that side PQ is the diameter of the circle.
Let O represent the center of the circle.
If the measure of arc QR is 40°, it means that the central angle formed by arc QR is 40°. Side OR and side OQ are equal because they are both radius of the circle. Therefore, ∆QOR is an isosceles triangle and the base angles are equal.
Therefore, ∠PQR = ∠ORQ
Since the sum of the angles in a triangle is 180°, then
∠PQR = (180 - 40)/2 = 140/2
∠PQR = 70°