when you divide 2 fractions, you reverse the second fraction then use multiplication
3/5 divided by 3/15 becomes
3/5 x 15/3 = 45/15 = 3
Well I'm not sure what the answer would be since I'm not that smart but I did get the answer of 90, I did this by dividing 72 by 80 which equals .9 and I multiplied that by 100 and got 90.
V=(4/3)(pi)(r^3)
V=(4/3)(pi)(8^3)
V=(4/3)(pi)(512)
V=(2048/3)(pi), or around 2144.660585
The first answer is figure B
the second is figure A because all angles are equal
the third is Hex regular
the 4th is octagon not regular
the 5th is hex regular
merry christmas my apologize for being to vague with my last answer