Question

find surface area and volume of a sphere of radius 7cm

Answer 1

Hope this helps you ☺☺☺

Answer 2

Given:

Radius of the sphere = 7cm

To Find:

Surface area and volume of the sphere.

Solution:

The formula to calculate the surface area of a sphere = 4πr²

where 'r' is the radius of the sphere and the value of π(pi) is 22/7 or 3.14.

In general, the surface area of a sphere is the amount of region covered by the surface of the sphere.

Now, putting the values in the formula to calculate the surface area

The surface area of a sphere = 4πr²

                                                 = 4 × 22/7 × 7 × 7  [radius is given as 7cm]

                                                 = 88 × 7

                                                 = 616 cm²

∴ The surface area of the sphere is 616cm².

The formula to calculate the volume of the sphere is 4/3πr³

Now, substituting the values in the formula to find the volume of the sphere,

The volume of the sphere = 4/3πr³

                                           = 4/3 × 22/7 × (7)³

                                           = 4/3 × 22/7 × 7 × 7 × 7

                     Simplifying the expression we get

                                           = 4312/3 cm³

                       This can also be written as,

                                           = 1437.33cm³

Therefore, the volume of the sphere = 1437.33cm³.