#### Question

In the given figure, if O is the centre of the circle, PQ is a chord. \[\angle\] POQ = 90^{°}, area of shaded region is 114 cm^{2} , find the radius of the circle. \[\pi\] = 3.14)

#### Solution

∠POQ = *θ* = 90º

Let the radius of the circle be *r *cm.

Area of the shaded region = Area of the segment PRQ = 114 cm^{2}

\[\therefore r^2 \left( \frac{\pi\theta}{360° } - \frac{\sin\theta}{2} \right) = 114\]

\[ \Rightarrow r^2 \left( \frac{3 . 14 \times 90° }{360° } - \frac{\sin90° }{2} \right) = 114\]

\[ \Rightarrow r^2 \left( \frac{3 . 14}{4} - \frac{1}{2} \right) = 114\]

\[ \Rightarrow r^2 \times \left( 0 . 785 - 0 . 5 \right) = 114\]

\[ \Rightarrow r = \sqrt{\frac{114}{0 . 285}}\]

\[ \Rightarrow r = \sqrt{400} = 20 cm\]

Thus, the radius of the circle is 20 cm.

Is there an error in this question or solution?

Solution In the Given Figure, If O is the Centre of the Circle, Pq is a Chord. ∠ Poq = 90°, Area of Shaded Region is 114 Cm2 , Find the Radius of the Circle. π = 3.14) Concept: Areas of Sector and Segment of a Circle.