1. **State the problem:** Find the area of a trapezoid given its bases and height. 2. **Formula:** The area $A$ of a trapezoid is given by $$A = \frac{(b_1 + b_2)}{2} \times h$$ where $b_1$ and $b_2$ are the lengths of the two parallel bases, and $h$ is the height (the perpendicular distance between the bases). 3. **Important rules:** - The bases must be parallel. - The height must be perpendicular to the bases. 4. **Intermediate work:** - Identify the lengths of the two bases $b_1$ and $b_2$. - Identify the height $h$. - Substitute these values into the formula. - Simplify the expression to find the area. 5. **Example:** Suppose $b_1 = 8$, $b_2 = 5$, and $h = 4$. Calculate: $$A = \frac{(8 + 5)}{2} \times 4 = \frac{13}{2} \times 4$$ Show cancellation: $$A = \cancel{\frac{13}{2}} \times \cancel{4} = 13 \times 2 = 26$$ 6. **Final answer:** The area of the trapezoid is $26$ square units.