Definition:
The total distance around the outside of a
parallelogram

Try this
Drag any orange dot to resize the parallelogram. The perimeter is calculated as you drag.
Drag point D to change the base length.

How to find the perimeter of a parallelogram

Like any polygon, the perimeter is the total distance around the outside,
which can be found by adding together the length of each side.
In the case of a parallelogram, each pair of opposite sides is the same length,
so the perimeter is twice the base plus twice the side length. Or as a formula:

perimeter = 2(w+h)

where: w is the base length of the parallelogram h is the side length

In the figure above, drag any orange dot to resize the parallelogram. From the side lengths shown, calculate the perimeter
and verify your result matches the formula at the top of the diagram.