Convex quadrilaterals are organised into a hierarchy of inclusions: each category is a particular case of the one containing it. The square, at the top, is at the same time a rhombus and a rectangle.
In summary — Hierarchy of convex quadrilaterals
Each level is a particular case of the previous one: the square is both a rhombus and a rectangle.
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Topics: Euclidean geometry
Concepts: Parallelogram · Square · Quadrilateral · Rectangle · Rhombus · Trapezium