To find the area on the rectangular deck:
Area needed = Area of rectangle - Area of triangle.
Area of rectangle:
[tex]\begin{gathered} A\text{ = b x h} \\ A\text{ = 30 ft x 15 ft} \\ A\text{ = 450 ft}^2 \end{gathered}[/tex]
Area of triangle:
[tex]\begin{gathered} A\text{ = }\frac{b\text{ x h}}{2} \\ \\ A\text{ =}\frac{20\text{ ft x 8 ft}}{2} \\ \\ A\text{ = 80 ft}^2 \end{gathered}[/tex]
Area needed = 450 ft² - 80 ft² = 370 ft²
