The numerical values of volume and whole surface area of a solid hemisphere are equal, let us write the length of radius of the hemisphere.

Let us write whether the following statements are true of false.

i. If we double the length of radius of a solid sphere, the volume of sphere will be doubled.

ii. If the ratio of curved surface areas of two hemispheres is 4 : 9, the ratio of their lengths of radii is 2 : 3.

Let us fill in the blanks.

i. The name of solid which is composed of only one surface is _______.

ii. The number of surfaces of a solid hemisphere is ___________.

iii. If the length of radius of a solid hemisphere is 2r units, its whole surface area is __________ π r² sq units.

The curved surface area of a solid sphere is equal to the surface area of a solid right circular cylinder. The lengths of both height and diameter of cylinder are 12 cm. Let us write the length of radius of the sphere.

Whole surface area of a solid hemisphere is equal to the curved surface area of the solid sphere. Let us write the ratio of lengths of radius of hemisphere and sphere.