Explanation:
Parallelogram
Parallelogram

This parallelogram is a rhomboid as its angles are oblique.

Type

quadrilateral

Edges and vertices

4

Symmetry group

C_{2}, [2]^{+},
(22)

Area

B × H;
ab sin θ

Properties

convex

In geometry, a parallelogram is a quadrilateral with two pairs of parallel sides. In Euclidean Geometry, the opposite or
facing sides of a parallelogram are of equal length and the opposite angles of
a parallelogram are of equal measure. The congruence of opposite sides and
opposite angles is a direct consequence of the Euclidean Parallel Postulate and
neither condition can be proven without appealing to the Euclidean Parallel
Postulate or one of its equivalent formulations. The threedimensional
counterpart of a parallelogram is a parallelepiped.
Area
formulas
The
area of the parallelogram is the area of the blue region, which is the interior
of the parallelogram
§ The
area of the parallelogram to the right (the blue area) is the total area of the
rectangle less the area of the two orange triangles.
The area of the rectangle is
and the area of a single orange triangle is
Therefore, the area of the parallelogram is
(Our solved example in mathguru.com uses this concept)
http://en.wikipedia.org/wiki/Parallelogram
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