### Topic Page: Parallelograms

**parallelogram**

*The Hutchinson Unabridged Encyclopedia with Atlas and Weather Guide*

A quadrilateral (a shape with four sides) with opposite pairs of sides equal in length and parallel, and opposite angles equal. The diagonals of a parallelogram bisect each other. Its area is the product of the length (l) of one side and the perpendicular distance (height h) between this and the opposite side; the formula is A = l × h. In the special case when all four sides are equal in length, the parallelogram is known as a rhombus, and when the internal angles are right angles, it is a rectangle or square.

For example, to find the area of a parallelogram 12 cm long and 6 cm high:

A = l × h, so

A = 12 × 6 = 72 cm^{2}

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parallelogram

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