Using disks ...

The volume is 21π units³ ≈ 65.97 units³
If there is 5/6 left and he plans to eat 1/6 you do 5/6-1/6=4/6 of the pie
A. Its a square. This means each side times the side would give us the area (s^2)
4/3^2 or 1.3333 x 1.33333 = 16 / 9 area.
B. Really just pick any numbers you want.
16 yards long and 1/9 wide.
As long as they multiply to 16/9
The answer should be 9 rounded because 2 pi r 56.5 will give u that.