Find the surface area of a cone with volume 320pi and height 15 (hint: don't use the height in the surface area formula.

Answer key :
Either 200 pi or 325 pi
Please help !!!

200π

Step-by-step explanation:

Surface area of a cone  = πr(r+l)

r is the radius

l is the slant height

Volume of the cone = 1/3πr²h

320π = 1/3πr²h

320 = 1/3r²(15)

320 = 5r²

r² = 320/5

r² = 64

r = 8

l² = 15² + 8²

l² = 225 + 64

l² = 289

l = 17

Get the surface area;

S =  πr(r+l)

S =  π8(8+17)

S = π*8*25

S = 200π

Hence the surface area of the cone is 200π

based on context clues you gave i'm assuming the answer would be c.

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i