Parallelogram

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Parallelogram
Parallelogram.svg
This parallelogram is a rhomboid as its angles are oblique.
Type quadrilateral
Edges an vertices 4
Symmetry group C2, [2]+, (22)
Aurie b × h;
ab sin θ
Properties convex

In Euclidean geometry, a parallelogram is a simple (non self-intersectin) quadrilateral wi twa pairs o parallel sides. The opposite or facin sides o a parallelogram are o equal length an the opposite angles o a parallelogram are o equal measur. The congruence o opposite sides an opposite angles is a direct consequence o the Euclidean Parallel Postulate an neither condeetion can be proven wioot appealin tae the Euclidean Parallel Postulate or ane o its equivalent formulations. The three-dimensional coonterpairt o a parallelogram is a parallelepiped.

The etymology (in Greek παραλληλ-όγραμμον, a shape "o parallel lines") reflects the defineetion.