\[
\text{Area} = \frac{1}{2} \times h \times (a + b)
\]
\[
\text{Where:}
\]
\[
\text{h = height (perpendicular distance} \]
\[
\text{between the parallel sides).}
\]
\[
\text{a = length of the first side.}
\]
\[
\text{b = length of the second side (parallel to } a \text{).}
\]
