A semicircle is drawn with AB as its diameter. From C, a point on AB, a line perpendicular to AB is drawn meeting the circumference of the semi-circle at D. Given that AC = 2 cm and CD = 6 cm, the area of the semicircle (in sq. cm) will be:

- 32 π
- 40.5 π
- 50 π
- 81 π

**Answer**

Angle in a semi-circle is a right angle.

∠ADC = 90°

CD^{2} = AC × CB

AC = 2 cm and CD = 6 cm

CB = 18 cm

Hence, AB = AC + CB = 20 cm

Radius of semicircle = 10 cm

Area of semi-circle = 1/2 * π * r^{2 }= 50 π

**The correct option is C.**