Select one pair of sides of the parallelogram as the base sides. It doesn't matter which pair of sides because both pairs of sides must be parallel and congruent.
Measure the distance between the two base sides to find the height of the parallelogram.
Measure the length of one of the base sides. It does not matter which side you measure because they are congruent so it will be the same length.
Multiply the base length times the height to find the area of the parallelogram. In this example, if the height equals 5 inches and the base equals 9 inches, multiply 5 by 9 to get an area of 45 square inches.