Perimeter of a rhombus is calculated by adding the length of its sides together. Since all rhombus sides are equal in length, its perimeter can also be calculated by multiplying the length of a side by 4.

**P = A + B + C + D**

or

**P = A × 4**

Where *P* is the perimeter and *A*, *B*, *C*, and *D* are the sides of the rhombus.

Example:

If A = 5 units then P = ?

P = A × 4 = 5 × 4 = 20