Formula for the area of a circle

Write the formula for the area of a sector of angle theta (in degrees) of a circle of radius r .

Write the formula for the area of a segment in a circle a circle of radius r given that the sector angle is theta (in degrees).

The radius of a circle is 14cm. Find the radius of the circle whose area is double of the area of the circle.

The area of a square is equal to the area of a circle. What is the ratio between the side of the square and the radius of the circle?

If the sum of the areas of two circles with radii R_(1) and R_(2) is equal to the area of a circle of radius R, then

If the sum of the areas of two circles with radii R_1 and R_2 is equal to the area of a circle of radius R, then

A square and a circle have equal perimeters. The ratio of the area of the square to the area of the circle is

A square and a circle have equal perimeters. The ratio of the area of the square to the area of the circle is

If diameter of a circle is r cm, then the area of a circle is :