To find the area of Keeshana's wall, we must first remember the formula for finding the area of a rectangle.
A = length * width
If we plug in our values for the length and the width that we are given in this problem, we can then perform the operations and find our answer.
Area = 9 feet * 11 feet
To solve, we simply multiply these two numbers together. Remember though, that because we are multiplying the numbers together we also must multiply the units together, which will give us a squared unit.
Area = 99 feet²
Therefore, the area of Keeshana's wall is 99 feet².
Hope this helps!