Question

Find the radius of a sphere with a surface area of 804 cm^2.

Answer 1

Surface area of sphere equals its four radii squared multiplied by the number π.
 We have then:
 A = 4 * π * R ^ 2
 Substituting:
 804 = 4 * π * R ^ 2
 Clearing the value of R we have:
 R = root (804 / (4 * π))
 R = 7.99876785 cm
 Nearest whole number:
 R = 8 cm
 Answer:
 The radius of a sphere is:
 B. 8cm