How do I find the perimeter of the region bounded by $\displaystyle y=e^x, y=0, x=0, $and $\displaystyle x=1$?

Mainly I need to know how to find the length of $\displaystyle e^x$ from 0 to 1. I know that once I get this number I can just add the other sides (1, 1, and e^1).