The Lesson
A square is a four sided shape with four equal sides and four right angles.Dictionary Definition
The Oxford English Dictionary defines a rectangle as "a plane rectilinear and rectangular figure with four equal sides."Properties of Squares

All sides of a square are of equal length.

All angles in a square are right angles.

Opposite sides of a square are parallel.

All angles of a square add up to 360°.

The diagonals of a square bisect each other at right angles. The diagonals cross each other halfway along their lengths and are perpendicular to each other.
The Perimeter of a Square
The perimeter of a square is given by the formula:In this formula, a is the length of the side of the square.
The Area of a Square
The area of a square is given by the formula:In this formula, a is the length of the side of the square.
Read more about how to find the area of a square
Interactive Widget
Here is an interactive widget to help you learn about squares.A Square is a Polygon
A square is a type of polygon. A polygon is a 2dimensional shape with straight sides. A square is a regular polygon. Regular polygons have the same length sides and the same angles.A Square Is a Quadrilateral
A square is a quadrilateral. A square is a foursided polygon. Parallelograms, rectangles and trapezoids are also quadrilaterals.Square Numbers...
A square number is a number multiplied by itself.
1^{2} = 1 × 1 = 1
2^{2} = 2 × 2 = 4
3^{2} = 3 × 3 = 9
The squares go 1, 4, 9...
A square with side length 1 has an area of 1.A square with side length 2 has an area of 4.
A square with side length 3 has an area of 9.
The areas go 1, 4, 9... The square of a number and the area of a square with side lengths of that number are the same.