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.....
Answer:
Step-by-step explanation:
Rewrite equation: 
Factor out 
:
Divide both sides by 
:
Anything to the power of 1 is itself. Hence,
2(exponent2)n(exponent11)p(exponent6)
Let the number of rows be x
rows = x
seats in each row = x + 20
total seats = 1344
x (x + 20) = 1344
x^2 + 20x - 1344 = 0
(x + 48)(x - 28) = 0
x = -48 (rejected, answer cannot be negative) or x = 28
Therefore,
x = 28
x + 20 = 48
Check:
Row = 28
Numbers of seat per row = 28 + 20 = 48
28 x 48 = 1344 (Correct)
Ans:There are 48 seats per row
