Answer :
Surface Area of a Sphere
Given a sphere of radius r, the surface area is calculated by:
[tex]S=4\pi r^2[/tex]The diameter of the paintball is d = 2.8 cm, thus the radius is r = 1.4 cm
The amount of paint on the sphere is equivalent to the surface area, or:
[tex]S=4\pi(1.4\operatorname{cm})^2=24.63\operatorname{cm}^2[/tex]