1. **State the problem:** We need to find the area of a trapezoid with bases of lengths 18 inches and 7 inches, and a height of 20 inches. 2. **Formula for the area of a trapezoid:** $$\text{Area} = \frac{1}{2} \times (\text{Base}_1 + \text{Base}_2) \times \text{Height}$$ 3. **Identify the values:** - Base 1 ($b_1$) = 18 inches - Base 2 ($b_2$) = 7 inches - Height ($h$) = 20 inches 4. **Substitute the values into the formula:** $$\text{Area} = \frac{1}{2} \times (18 + 7) \times 20$$ 5. **Simplify inside the parentheses:** $$18 + 7 = 25$$ 6. **Calculate the area:** $$\text{Area} = \frac{1}{2} \times 25 \times 20 = \frac{1}{2} \times 500 = 250$$ 7. **Final answer:** The area of the trapezoid is $250$ square inches.