Answer: 4
Explanation:
2^2=2*2=4
So the best and correct answer is C because this is how you do it The surface area of the cone has formula
pi * radius * ( radius + sqrt ( height^2 + radius^2)) =
pi * radius^2 + pi * radius * sqrt( height^2 + radius^2)
However, this includes the base of the cone and the hats do NOT have
that. "The hats are shaped like a cone with NO BASE", says the 3rd sentence.
So the formula becomes pi * radius * sqrt( height^2 + radius^2)
diameter = 16
radius = 8
height = 9
The surface area of ONE of the hats is pi * 8 * sqrt( 9^2 + 8^2)
= pi * 8 * sqrt( 81+64)
= pi * 8 * sqrt(145)
302.63828053.....
21 of them is 21 * 302... = 6355.40689112841343251026086.....
It would be C. 0.14. You add together the rest of the decimals which gets you 0.86 and subtract them from 100,
