Monte Carlo Pi
Drop random points into a square and count how many fall inside the quarter circle. The ratio approximates π/4, so the estimate converges to π.
Frequently Asked Questions
Why does this work?+
The quarter circle covers π/4 of the square. With enough random points, the fraction inside the circle approaches π/4, giving an estimate of π.
How accurate is it?+
Accuracy grows with the number of points. With 200,000 points you typically get π correct to about 2-3 decimal places.