# Square (geometry)

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 < xi < 1.

• Triangle with two squares  (http://agutie.homestead.com/files/triangle_square0.htm) by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with two squares I (http://agutie.homestead.com/files/triangle_squares1.html) by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with two squares II (http://agutie.homestead.com/files/Geoproblem_B.htm#triangleSquares2) by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with three squares III (http://agutie.homestead.com/files/Geoproblem_B.htm#triangleSquares3) by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with two squares IV  (http://agutie.homestead.com/files/Finsler_Hadwiger.htm) Finsler-Hadwiger Theorem by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with two squares V (http://agutie.homestead.com/files/triangle_squares5.htm) Median and Altitude by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Triangle with four squares VI (http://agutie.homestead.com/files/triangle_squares6.htm) by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Van Aubel's theorem (http://agutie.homestead.com/files/vanaubel.html) Quadrilateral with four squares by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"
• Parallelogram with five squares (http://agutie.homestead.com/files/parallelogram_squares.htm) by Antonio Gutierrez from "Geometry Step by Step from the Land of the Incas"bg:Квадрат

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