Answer:
640.5 cm^2
Step-by-step explanation:
So the formula for trapezoid is height times the average of the bases. So 25+36=61, and then we divide that by 2 to get 30.5 as our average. Then, we take 30.5 and multiply it by 21 and we get 640.5.
Notice the picture below, see the length "l"?
well

solve for "w", to find the width,
what's the length? well, l = 11/4 w
The answer is [ all real numbers ]
The domain are the input values which makes the function defined and real.
Since we don't have any constraints or any undefined points, the domain could be literally anything. Thus proves out answer.
Best of Luck!
Area of Rectangle = Width × Length
Area = 600 Sq ft
Width = 20
Length = L
20L = 600
L = 600/20 = 30
Floor is 30' long