In ΔEFG, the measure of ∠G=90°, FG = 21 feet, and EF = 63 feet. Find the measure of ∠E to the nearest degree.

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?