Question

In the above figure, O is the center of the circle and, M and N lie on the circle.
The area of the right triangle MON is $50c{m}^2$. What is the area of the circle in $c{m}^2$?

• A.
  $2\pi$
• B.
  $100\pi$
• C.
  $50\pi$
• D.
  $75\pi$

Answer 1

The correct option is B

$100\pi$
$\because \text{Area of}\Delta MON=50c{m}^2$

$\frac{1}{2}\times r\times r=50$

$r^2=100$

$Areaofcircle=\pi r^2$

$=\pi \times 100$

$=100\pi$