A **sphere** is a solid in which all the points on the round surface are equidistant from a **fixed point,** known as the center of the sphere. The distance from the center to the surface is the **radius**.

Surface area of a sphere is given by the formula

**Surface Area of sphere = 4π r^{2}**

where *r* is the radius of the sphere.

*DEMONSTRATION:*

Calculate the surface area of a sphere with radius 2.2 cm

*Solution:*

Surface area of sphere

= 4*π r*^{2}

= 4*π* (2.2)^{2}

= 4 × 3.14 × 2.2 × 2.2

= 60.79 cm^{2}