A regular quadrilateral is a a four sided shape that has all of its sides equal in length. There are two shapes that satisfy these conditions, a square and a rhombus.
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A regular quadrilateral is a shape with four sides which are all the same
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It is called a square. "Regular" means all four angles are the same, and all four sides are the same. Source(s) http://en.wikipedia.org/wiki/Square_28g….
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In plane geometry, a quadrilateral is a polygon with four sides (or 'edges') and 4 vertices or corners.
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