Rectangular means having the shape of a rectangle: a flat, four-sided figure with four right angles (square corners) and opposite sides that are equal and parallel. Picture a door, a book, a soccer field, or a dollar bill. All these objects are rectangular.

Most rooms in houses are rectangular because this shape uses space efficiently and makes furniture arrangement straightforward. Rectangular gardens are easier to measure and fence than irregular shapes. Builders and architects favor rectangular designs because right angles make construction simpler and stronger.

Often, a rectangle is longer in one direction than the other. If all four sides are equal, the shape is a square, which is a special type of rectangle.

You'll see rectangular shapes everywhere once you start noticing them: windows, tablets, swimming pools, parking spaces, and basketball courts. When someone describes a table as rectangular, they're telling you it has that familiar four-cornered shape with straight sides and sharp corners, not round, oval, or irregularly shaped.