Find the surface of a sphere with a diameter of 40 inches. Leave your answers in terms of pi

Answer 1

The formula for the surface area \( A \) of a sphere is given by:

\[ A = 4\pi r^2 \]

where \( r \) is the radius of the sphere.

Since the diameter of the sphere is 40 inches, we can find the radius by dividing the diameter by 2:

\[ r = \frac{40}{2} = 20 \text{ inches} \]

Now, substituting the radius into the surface area formula:

\[ A = 4\pi (20)^2 \] \[ A = 4\pi (400) \] \[ A = 1600\pi \]

Therefore, the surface area of the sphere is

\[ \boxed{1600\pi} \text{ square inches.} \]