Geometry Help

Area of a Parallelogram

Today we are going to calculate the area of a parallelogram. But, of course, we must first define what a parallelogram is.

What is a parallelogram?

A parallelogram by definition has four sides. In the picture shown, the sides are labelled just a and b because the opposite sides of a parallelogram must be of the same length. However, unlike a rectangle, the sides do not have to be perpendicular to one another. In another word, a rectangle is a parallelogram with perpendicular sides.


So, if you have a geometrical shape with both opposite sides parallel to each other, then you have a paralellogram.

Area of a parallelogram

Now, with each parallelogram, there is a perpendicular height between the two parallel sides. The perpendicular height from the base b of the parallelogram is labelled 'h'. The formula for calculating the area of a parallelogram is simply this.

Formula for area of parallelogram

Formula for area of parallelogram

In another word, the area of a parallelogram is its base times its perpendicular distance to the opposite parallel side. Now, whether you measure h from b or from a, the resulting area of the parallelogram will be the same.

Area of parallelogram In another word, a x h1 = b x h.