## Squares

##### Definition of a square

- A square is a quadrilateral that is both a rectangle and a rhombus.

##### Properties of a square

- The opposite sides of a square are parallel.
- All sides of a square are equal.
- All angles of a square are right angles.
- The diagonals of a square meet each side at 45 °.
- The diagonals of a square are equal and bisect each other at right angles.

##### Test for a square

- The quadrilateral must be both a rectangle and a rhombus.
- The diagonals of the quadrilateral are equal and bisect each other at right angles.