## Algebra: A Combined Approach (4th Edition)

$64\pi$ square inches
Let $A$ be the surface area of a sphere. Let $r$ be the radius of a sphere. $A=kr^2$ $A=36\pi ; r=3$ $36\pi=k(3)^2$ $k=4\pi$ $A=4\pi r^2$ $r=4$ $A=4\pi (4)^2$ $A=64\pi$ square inches