Children are tested by Bad man to identify parallel and perpendicular edges and faces.

Numbers 10 and 6 discover the joys of being 16. As the number 16, they impress number 4 as they show all the ways they can be a square.

The shapes introduce themselves and their characterisitcs to the square.

Finn tries to impress Princess Bubblegum with a bubble blower capable of blowing bubbles in different dimensions. Unfortunately, a 4th-dimensional bubble means a black hole.

Number 12 sings about the different shapes and arrays that they can become.