The shape of the room is not a square.
Pythagorean Theorem: 17^2+17^2= 578, square root 578 and you'll get 24.04.
The length of the diagonal of the floor of the room in the plan should have been 24.04 in order to be a square.
Well the answer I got was closest to 71.
3.14 x radius squared = area
If you divide 4040 by 3.14 you get radius squared which is 1286.6242
If you square root it you get the radius which is 35.869544
If you multiply the radius by 2 you get diameter which is about 71.739088
