The area of the polygon with vertices at (0, 9), (7, 9), (9, 0), (0, -8), and (-10, 0) is 45 square units.
To calculate the area of the five-sided polygon formed by vertices A(0, 9), B(7, 9), C(9, 0), D(0, -8), and E(-10, 0), you can divide it into two triangles and apply the Shoelace Formula.
1. **Triangle ABC:**
Use the Shoelace Formula with vertices A, B, and C:
![\[ \text{Area}_(ABC) = (1)/(2) \left| (0 * 9 + 7 * 0 + 9 * 9) - (9 * 7 + 0 * 0 + 0 * 9) \right| \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/udoykjzhsi4qo1yy39i74z3zphaucjl9az.png)
Simplifying,

2. **Triangle ACD:**
Use the Shoelace Formula with vertices A, C, and D:
![\[ \text{Area}_(ACD) = (1)/(2) \left| (0 * 0 + 9 * (-8) + 0 * 9) - (9 * 0 + (-8) * 0 + 0 * 0) \right| \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/e3kt68fn85v5nq582rx8vk8hljsadidrh0.png)
Simplifying,

Now, sum the areas of both triangles:
![\[ \text{Total Area} = \text{Area}_(ABC) + \text{Area}_(ACD) = 9 + 36 = 45 \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/9hqfj9p706qyhxw8wihmio53izxax7o05q.png)
Therefore, the area of the lot is 45 square units.