Parallelograms - area

The area of a parallelogram is the base \times perpendicular~height~(b \times h).

Area of a parallelogram diagram

You can see that this is true by rearranging the parallelogram to make a rectangle.

Area of a parallelogram diagram

Rearranging a parallelogram

Regular parallelogram showing base and height.

curriculum-key-fact
Use the perpendicular height of the parallelogram, not the sloping height.
Question

Find the area of this parallelogram:

Area of a parallelogram diagram

The area is {7~cm}\times{3~cm}={21~cm}^{2}.

Remember to use the perpendicular height of the parallelogram.