Perimeter of a trapezoid is the total distance around it and it is calculated by summing the length of all its four sides.

**P = a + b + c + d**

Where *P* is perimeter, and *a*, *b*, *c*, and *d* are the sides of the trapezoid.

Example:

If: a = 4, b = 8, c=3, and d = 5

then P = ?

P = a + b + c + d = 4 + 8 + 3 + 5 = 20 unites