Answer:
160 ft^2
Explanation:
First you have to find the width, then you find the area. To find the width with a percentage we do Part/ Total = %/100 and we cross multiply. We need to find the part so that is the unknown, we will call it 'w' for width
w/20 = 40/100 Now we cross multiply, the x and the 100 and the 20 and 40
w * 100 = 100w
20 * 40 = 800
Now we have 100w = 800 The next step is to divide both sides by 100 so we just have w
100x/100= w
800/100 = 8
w = 8
The width is 8
Now we find the area which is length x width
20 x 8 = 160
So the area is 160 ft^2