1. **Stating the problem:** Calculate the area of the irregular polygon described, which resembles a trapezoid with a rectangular notch cut out from the bottom-left interior. 2. **Formula and approach:** The area of an irregular polygon can be found by decomposing it into simpler shapes (rectangles, trapezoids) and subtracting the area of the notch. 3. **Identify dimensions:** - The left side height is 15 units. - The right side height is 9 units. - The bottom side is divided into two parts: 3 units (notch width) and 10 units (main base). - The notch height is 4 units. - The top side length is 8 units. 4. **Calculate the area of the main trapezoid:** The trapezoid has parallel sides of lengths 15 (left height) and 9 (right height), and a base length of 13 (3 + 10). Area of trapezoid = $$\frac{(a+b)}{2} \times h = \frac{(15+9)}{2} \times 13 = \frac{24}{2} \times 13 = 12 \times 13 = 156$$ 5. **Calculate the area of the rectangular notch:** Area of notch = width \times height = 3 \times 4 = 12 6. **Calculate the area of the irregular polygon:** Area = Area of trapezoid - Area of notch = 156 - 12 = 144 **Final answer:** $$\boxed{144}$$