Area of a circle

Q.

What is the area of a circle with radius r units?

1. $\pi r^2$

2. $r^2$

3. $4\pi r^2$

4. $2\pi r^2$

Q. The adjacent figure shows two arcs P and Q. Arc P is part of the circle with centre O and radius OA. Arc Q is a part of the circle with centre M and radius AM, where M is the mid-point of AB. Area enclosed by the arc AQB and chord AB

1. $25\pi c{m}^2$
2. $\frac{25}{2}\pi c{m}^2$
3. $\frac{20}{2}\pi c{m}^2$
4. $20\pi c{m}^2$

Q.

In a grass field, a bull is tied to a pole with a rope of length 7 meters. How much area of field is it allowed to be grazed?
$(Take\pi =\frac{22}{7}$)

1. 154 $m^2$

2. 55 $m^2$

3. 110 $m^2$

4. 100 $m^2$