SOLUTION: The surface area, S, of a cone of radius r and h can be found using the formula S=πr√r^2+h^2. What is the height of this cone? S= 225 cm^2 r= 5 cm

Algebra ->  Radicals -> SOLUTION: The surface area, S, of a cone of radius r and h can be found using the formula S=πr√r^2+h^2. What is the height of this cone? S= 225 cm^2 r= 5 cm      Log On


   



Question 1117077: The surface area, S, of a cone of radius r and h can be found using the formula S=πr√r^2+h^2. What is the height of this cone?
S= 225 cm^2
r= 5 cm

Found 3 solutions by Boreal, Alan3354, ankor@dixie-net.com:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
225=pi*r (r+sqrt(r^2+h^2)
225=5 pi(5+sqrt(h^2+25)
divide both sides by 5 pi
14.324=5+sqrt(h^2+25)
9.324=sqrt(h^2+25)
86.84=h^2+25, after squaring both sides
61.84=h^2
h=7.86 cm

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
the formula S=+pi%2Ar%2Asqrt%28r%5E2%2Bh%5E2%29. What is the height of this cone?
S= 225 cm^2
r= 5 cm
--------------
225+=+pi%2A5%2Asqrt%2825+%2B+h%5E2%29
Solve for h
==========================================
Now what?
2 "solutions," 2 different numbers.
You might have to do it, and learn how to do it.
Both of them show you how to do it.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The surface area, S, of a cone of radius r and h can be found using the formula
S+=+pi%2Arsqrt%28r%5E2%2Bh%5E2%29
What is the height of this cone?
S= 225 cm^2
r= 5 cm
:
pi%2A5sqrt%285%5E2%2Bh%5E2%29=225
divide both sides by 5
pi%2Asqrt%2825%2Bh%5E2%29+=+45
divide both sides by pi
sqrt%2825%2Bh%5E2%29+=+45%2Fpi
square both sides
25+%2B+h%5E2+=+%2845%2Fpi%29%5E2
25+%2B+h%5E2+=+205.175%7D%7D%0D%0A%7B%7B%7Bh%5E2+=+205.175+-+25
h%5E2+=+180.175
h = sqrt%28180.175%29
h = 13.43 cm