Gif Central boasts hundreds of funny animated gifs. Only the best of the best make it onto this site, with most of them having an accompanying source. No tumblr-esque one-second-long disappointments. No obscure titles or descriptions.
This is an animated gif that gives you a visual explanation of why Pi is considered to be 3.14159. In case you didn't already know, Pi is the ratio of a circle's circumference to its diameter. Often represented by the greek letter π.