You seem to be unaware of the fact that you could have obtained the answer much more easily and quickly by using the calculator that comes as part of your computer.
Sqrt(347.473456) = 18.6, approx.
six on the square root of three
1.7724538509......
1000
8
39.68626967
11.1803398
19
35.805
the diagnol is the side of the square times squareroot(2) so the length of the side is 11/squareroot(2) and in simplified form your final answer is 11*squareroot(2)/2
sqrt(112) = 10.58301
29 29X29=841
The answer is squareroot r2+h2 squareroot radiusxradius + heightxheight