To find the area defined by the dimensions 10 ft, 10 ft, and 9 ft, it seems you are referring to a shape such as a triangle where 10 ft and 10 ft could be the lengths of two sides, and the 9 ft could be the height or the base.
Assuming this forms an isosceles triangle:
To find the area \( A \) of this triangle, we can use the formula:
\[ A = \frac{1}{2} \times \text{base} \times \text{height} \]
If we consider "10 ft" as the base and "9 ft" as the height:
\[ A = \frac{1}{2} \times 10 , \text{ft} \times 9 , \text{ft} = \frac{1}{2} \times 90 , \text{ft}^2 = 45 , \text{ft}^2 \]
So, the area is:
\[ \boxed{45} , \text{ft}^2 \]