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.

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 :

If the perimeter and the area of a circle are numerically equal, then the diameter of the circle is

If radius of circle if 4r, the area of circle is equal to :