###### Example2.1.10Geometry

An expression for the area of a trapezoid (shown in FigureĀ 2.1.11) is \(\frac{1}{2}(a+b)h\text{,}\) where \(a\) and \(b\) are the parallel side lengths and \(h\) is the height. This expression is valid if \(a\text{,}\) \(b\text{,}\) and \(h\) are all measured in centimeters, inches, or any other unit for length. The result will be measured in square units, such as cm^{2} or in^{2}.

Determine the area of a trapezoid for which \(a=3\,\text{cm}\text{,}\) \(b=5\,\text{cm}\text{,}\) and \(h=2\,\text{cm}\text{.}\)