Please answer ASAP! Thank you in advance.

The other hint is - Use subtraction to find the lengths of the sides of the small rectangle.

I believe the answer is 5

Step-by-step explanation

12 - 7 = 5

128ft^2

Step-by-step explanation: the small rectangle at the top of the big rectangle sides are 4ft and 5 ft because 12-7=5 and 13-9=4. This means that the area for the small triangle is 20ft. The side lengths for the big rectangle is 9ft and 12ft which means that the area is 108ft. Then you add 108ft with 20ft which gives you 128ft. Dont forget to add the squared at the end of 128ft.