Need

what is the radius of a sphere when the surface area is 803.84 in2? use 3.14 for π.
a. 8 in.
b. 16 in.
c. 2 in.
d. 4 in.

what is the diameter of a sphere with surface area of 1256 in2? use 3.14 for π.
a. 10 in.
b. 12.56 in.
c. 20 in.
d. 5 in.

Well, to find the surface area of a circle it is 2 pi r. The question gives you the surface area so you divide that by 2 pi. That will give you the radius. For the second one you set it up the same but it'll give you the radius. The diameter is 2 times the radius so when you get the radius multiply the answer by 2 and that will give you the diameter.