It takes approximately 20 square inches of felt to cover a tennis ball.
Step-by-step explanation
A tennis ball is in shape of a Sphere. As the outside of the ball is covered with felt, so we need to find the surface area of the ball.
Formula for surface area of sphere:
![A= 4\pi r^2](https://img.qammunity.org/2019/formulas/mathematics/high-school/9zduz0rzzqsiady9qnl7eckdkne0o6z3hr.png)
where,
is the radius of the sphere.
Here the radius is given as 1.25 inch, so
![r=1.25](https://img.qammunity.org/2019/formulas/mathematics/high-school/w5sgp8r1gp61e4wuyfz0rqg1yohnwfr9c8.png)
Thus,
![A= 4\pi (1.25)^2\\ \\ A= 4(3.14)(1.5625)\\ \\ A= 19.625\\ \\ A= 20 (Approximately)](https://img.qammunity.org/2019/formulas/mathematics/high-school/96b5bw37bjtdptxkq4gfck1igx1gzcxrlw.png)
So, it takes approximately 20 square inches of felt to cover a tennis ball.