A square is a regular quadrilateral, which means that it has four equal sides and four equal angles
- In geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90-degree angles, or 100-gradian angles or right angles).
- It can also be defined as a rectangle in which two adjacent sides have equal length.
- A rhombus with a right vertex angle
- A rhombus with all angles equal
- A parallelogram with one right vertex angle and two adjacent equal sides
- A quadrilateral with four equal sides and four right angles
- A quadrilateral where the diagonals are equal, and are the perpendicular bisectors of each other (i.e., a rhombus with equal diagonals)
Equation (where x & y are sides)