What is the surface area of the cylinder with height 5 km and radius 7 km? Round your answer to the nearest thousandth.
1 answer
The formula for the surface area of a cylinder is $2\pi r^2 + 2\pi rh$, where $r$ is the radius and $h$ is the height. Substituting in the given values, we have $$2\pi(7^2)+2\pi (7)(5)=2\pi(49)+2\pi(35)=98\pi+70\pi=\boxed{168\pi}$$ square kilometers. Note that the exact value of $\pi$ is not specified, so the answer is left in terms of $\pi$.