In plane geometry, a square is a polygon with four equal sides and equal angles. Those angles are then necessarily right angles. Squares are regular quadrilaterals, rectangles, rhombi, kites, parallelograms, and isosceles trapezoids/isosceles trapezia.

The diagonals of a square are equal and conversely, if the diagonals of a rhombus are proven to be equal, then that rhombus must be a square.

The coordinates for the vertices of a square centered at the origin and with side length 2 are (±1, ±1), while the interior of the same consists of all points (x₀, x₁) with -1 < x_i < 1.

External links

• Triangle with two squares by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with two squares I by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with two squares II by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with three squares III by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with two squares IV Finsler-Hadwiger Theorem by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with two squares V Median and Altitude by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with four squares VI by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Van Aubel's theorem Quadrilateral with four squares by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Parallelogram with five squares by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"