Why is aquare also a rectangle?

Answer 1

A rectangle is defined as a four sided figure with four right angles. Does any of that definition not meet with the definition of a square? No. A square is just a rectangle with all four sides equal length. ■

Answer 2

The word 'rectangle' means four(4) right angles.

A square has four(4) right angles.

Hence a square is a special form of rectangle.

A square has four sides of equal length.

A rectangle has two opposite sides of equal length.

Answer 3

A square is a rectangle because it possesses all the properties of a rectangle. These properties are: Interior angles measure 90 degrees each. Opposite sides that are parallel and equal.