Answer :

Answer:

8,000 square foot

Explanation:

Total space available 20,000 square foot.

60 percent  to be used. space left?

If 60% is will be used, only 40% will be availble for construction.

40% of 20,000= 40/100x 20,000

                          =0.4 x 20,000

                          =8,000 square foot