The value root of 40 of lies between which two consecutive integers

When you square  +6  or  -6  you get  36.  That's less than  40.

When you square  +7  or  -7, you get  49.  That's more than  40.

So one of the square roots of  40  is between  +6  and  +7, and
the other square root of  40  is between  -7  and  -6 .

If you make it a little more clear i can answer it

No he does not because he can only cover 12 square feet from 15 square feet which he will still need 3 more. this is because if 3×5=15 square feet and 15-12=3 which thats the answer