Carter speaks with Peter about a stunt he pulled involving music. He tells Peter that music is forbidden in prison, and Peter calls him obtuse. Carter creates an obtuse angle using his body and creates an acute angle soon after to show that he isn't obtuse.

The shapes introduce themselves and their characterisitcs to the square.

This video pairs a dance about angles, acute and obtuse, to a catchy beat.

When Number 4 jumps into Flatland, he becomes a square. Meet the rest of the shapes by counting the sides.

The straight line competes with the squiggly line to become more fun and win the heart of the perfect circle. The straight line eventually learns how to create angles and complex shapes in order to win over the circle.