In this Demonstration, we can throw Buffon's needles on the three types of grids, all with unit grid height : planks, squares, and triangles (known as single, double, and triple in statistics literature). When a needle is thrown at random on these planes, the number of possible crossings are two, three, and four, respectively. In the Demonstration, we can see the theoretical probabilities and the frequency ratios of these crossings. For each grid, as the number of needles gets larger, it could be expected that the difference between the estimated and actual values of would get smaller. We can also expect that as the ratio of needle length to grid height (i.e., ) grows, we get better estimates. The single grid (planks) is the most efficient in obtaining the tightest estimates of .