Sad Man introduces the concept of perpendicular lines and looks for examples of them in the real world. Bad Man tests two kids on their knowledge of math and asks them to create perpendicuar lines.
The CyberSquad cannot make a big enough square with the rods it has available, so Jackie suggests making a triangle. The group successfully forms a triangle and then attempts to make a square with two triangles unsuccessfully. When Digit creates a right triangle, the group tries again to combine the triangles into a square. This time, it is successful, and Jackie explans how to know they've formed a proper square.