Since a rectangle is made up of unequal parts, the measurements of the length, width and height are not the same. One or two of them must be longer than the other, depending on the physical appearance of the rectangle. After identifying the three measurements, record them on a piece of paper.
Use a calculator to find the volume of the rectangle by multiplying the length, width and height. However, when calculating the volume of a rectangle attached to a triangle, find the area of the base and multiply it by the height. The area of the base is found by multiplying the length by the width of the rectangle. The height, in this case, is the distance between the highest point of the triangle and the middle point of the rectangular base.
The standard unit for volume is cubic meters. Therefore, if the measurements of the rectangle are in cubic meters, the same unit has to be maintained in the final answer. The same case applies to measurements that are in cubic centimeters, millimeters and other numeric values.