A quadrilateral has two diagonals, and four equal sides with opposite sides equal called a parallelogram. In a parallelogram its sides never intersect but its diagonal intersects each other at the center point. The diagonal divides the parallelogram into two equal parts.
A parallelogram is a two-dimensional figure, and you can calculate its perimeter using the concept of mensuration. Mensuration involves calculating lengths, areas, perimeters, volumes, etc. of geometrical figures.
Parallelogram Properties
- The opposite sides of a rectangle are congruent
- Angles opposite each other are congruent
- All angles are right if one angle is right.
- Parallelograms are bisected by their diagonals.
The perimeter of a Parallelogram When Two Adjacent Sides Are Given
Parallelogram perimeters are calculated using the same formula as rectangle perimeters. Parallelograms have equal opposite sides, just like rectangles.
Perimeter of Parallelogram =
,
Perimeter of a Parallelogram When the Base, Height and Angle Are Given
The formula for the perimeter of a parallelogram when the base, height, and angle are given is derived using the properties of a parallelogram. Consider the picture below.
Here, “h” is the height and “b” is the base of the parallelogram while 
is the angle between the height CE and side CA of the parallelogram. If we apply 
to triangle ACE, we get,
Therefore, the formula of the perimeter of a parallelogram when the base, height, and angle are known can be written as:
Perimeter of parallelogram= 