Out of the Shade

Adapted from http://cemc.uwaterloo.ca/resources/potw/2014-15/POTWD-14-MT-NA-02-P.pdf, used with permission.

Using the information in the graphic below, write a program that outputs the area to the nearest 100th cm². Don't worry about the answer that involves pi.

Note: see http://stackoverflow.com/questions/3221654/specifying-number-of-decimal-places-in-python for information about printing to two decimal places.

(Click to enlarge)