Monte Carlo approximation of π

This program demonstrates a Monte Carlo approximation of π. The idea is that you plot random points in a square. The square's sides length is 2, so a concentric circle circumscribed within the square has a radius of 1. A point is within the circle if its distance from the center of the shapes is 1 or less. The ratio of points inside the circle to the total number of points is approximately π/4. Given a perfect random number generator, this ratio approaches the exact value of π/4 as the number of points increases. The value of π/4 is approximately . Almost all of the boilerplate code used in this program is copied from examples in Introduction to Computer Graphics by David J. Eck.