Parallelogram is a quadrilateral in which both pairs of the opposites are parallel. To find the area of a parallelogram first draw the diagram of a parallelogram. Parallelogram can be further divided into squares and rectangles. To calculate the area of both of these kinds of parallelograms multiply the length of the parallelogram with its height. In general the area of a parallelogram in obtained by multiplying the base of a parallelogram with its altitude. In square and rectangle cases, their altitude is nothing but their height, which is their other side. But in a general parallelogram there is no line perpendicular to the base, and hence you need to find out the altitude to get its area. Multiplying this altitude with the base gives you the area of the parallelogram. This video shows how to compute the area of a parallelogram.