In the diagram above, O is the center of the circle, |SQ| = |QR| and ∠PQR = 68°. Calculate ∠PRS
-
A.
34o -
B.
45o -
C.
56o -
D.
62o -
E.
68o
Correct Answer: Option A
Explanation
From the figure, < PQR = 68°
(therefore) < QRS = < QSR = (frac{180 – 68}{2}) (base angles of an isos. triangle)
= 56°
(therefore) < PRS = 90° – 56° = 34° (angles in a semi-circle)