For this case we have that the area of the rectangle is given by:
[tex]A = a * b[/tex]
Where:
a: It is the length of the rectangle
b: It is the width of the rectangle
According to the data we have to:
[tex]a = 21 \ feet\\b = 9 \ feet[/tex]
Replacing the data we have:
[tex]A = 21 * 9\\A = 189[/tex]
Finally, the floor area is [tex]189 \ ft ^ 2[/tex]
Answer:
[tex]189 \ ft ^ 2[/tex]
