How to Find the Perimeter and Area of a Parallelogram

So far, we have looked at rectangles and squares. Now we’ll look at another type of quadrilateral, the parallelogram.

A parallelogram is a quadrilateral where two sets of sides are parallel to each other, and two sets of sides are also of the same length. Opposite angles are also of the same size.

But what does it mean that two lines are parallel? Imagine train tracks, side by side. These two tracks always have the same distance between them. No matter how far the train goes, and in whatever direction, the distance between the two tracks always remains the same. Parallel lines have the same property. They will always be the same distance apart, and they’ll never cross.

Perimeter of a Parallelogram

To find the perimeter of the parallelogram you need to add the length of all the sides. Because each set of sides has the same length as each other, you only need to measure the length of the two different sides and multiply each of them by 2. This is the same as for the rectangle.

Area of a Parallelogram

A parallelogram is really a rectangle that has been shifted at the top and bottom. If you straightened it so that all angles were $90$°, you would get a rectangle.

To find the area of a parallelogram you need to know the length of one of the sides—the base—and the height of the parallelogram. The height is always measured at a $90$° angle to the base. When you have the base and the height you calculate the area in the same way as you would dofor the rectangle— you multiply the base and the height.