I loved this animation as a kid, it's still great now...
The Dot and the Line: A Romance in Lower Mathematics is a book written and illustrated by Norton Juster, first published by Random House in 1963. The story was inspired by Flatland: A Romance of Many Dimensions, in which the protagonist visits a one-dimensional universe called Lineland, where women are dots and men are lines.
In 1965, famed animator Chuck Jones and the MGM Animation/Visual Arts studio adapted The Dot and the Line into a 10-minute animated short film for Metro-Goldwyn-Mayer, narrated by Robert Morley. The Dot and the Line won the 1965 Academy Award for Animated Short Film. It was entered into the Short Film Palme d'Or competition at the 1966 Cannes Film Festival. (Source: Wikipedia)