In a circle with centre O, PQ and QR are two chords such that ∠ PQR = 118°. What is the measure of ∠ OPR ?
Answer & explanation
Correct answer: option 4

Let P and R meet at point S on the major segment of the circle
Now,
PQRS is a cyclic quadrilateral
So, \(\angle\)PSR + \(\angle\)PQR = \({180}^\circ\)
⇒ \(\angle\)PSR + \({118}^\circ\) = \({180}^\circ\)
⇒ \(\angle\)PSR = \({180}^\circ\) - \({118}^\circ\)
⇒ \(\angle\)PSR = \({62}^\circ\)
Now,
\(\angle\)POR = \({124}^\circ\)
OP = OR = radius of the circle
So, \(\angle\)OPR = (\({180}^\circ\) - \({124}^\circ\))/2
⇒ \(\angle\)OPR = \({56}^\circ\)/2
⇒ \(\angle\)OPR = \({28}^\circ\)
Therefore, \(\angle\)OPR is \({28}^\circ\).