The area of two-dimensional figures varies depending on the object. For the simpler two-dimensional figures (square, rectangle, parallelogram), the area can actually be found by calculating the number of square units in the interior of the object. Such a task can be difficult and time consuming, so mathematicians simply multiply the height (h) times the base (b), sometimes said as length times height or length times width (with rectangles). (For more information about the area of geometric figures, see the Appendix 2: Common Formulas for Calculating Areas and Volumes of Shapes).