A parallelogram is a 4-sided shape formed by two pairs of parallel lines. Opposite sides are equal in length and opposite angles are equal in measure. To find the area of a parallelogram, multiply the base by the height. The formula is: a=bh where b is the base and h is the height. The base and height of a parallelogram must be perpindicular. However, the lateral sides of a parallelogram are not perpendicular to the base. Thus, a dotted line is typically drawn to represent the height.