Right Angles Everywhere

A rectangle is a four-sided shape with four right angles. Opposite sides are equal and parallel. This simple definition produces the shape that dominates human construction — your room, your screen, this page, and nearly every building in every city on Earth.

Rectangles tile perfectly with zero waste, which is why bricks, tiles, and shipping containers are rectangular. Area equals length times width — the simplest area formula in geometry. Perimeter equals 2 times (length + width). A rectangle's diagonal splits it into two identical right triangles, linking rectangles directly to the Pythagorean theorem and making diagonal measurement a standard construction technique.