2007-06-04 15:44:40 · 3 answers · asked by 2 days after my B day :) 2 in Science & Mathematics ➔ Mathematics
V = (1/3)pi(r^2)(h)
100pi = (1/3)pi(r^2)(4)
75 = r^2
r = 8.66
2007-06-04 15:52:22 · answer #1 · answered by Kemmy 6 · 0⤊ 0⤋
The volume of a cone
=1/3*pi*r^2*h
here h=4
Therefore,
1/3*4*pi*r^2=100*pi
Therefore r^2=100*3/4[dividing both sides by1/3*4*pi)
r^2=75
r=8.66 units
2007-06-04 23:15:16 · answer #2 · answered by alpha 7 · 0⤊ 0⤋
h = 4
V = 100 pi
V = (1/3) * (pi) * (r^2) * h
100 pi = (1/3) * pi * r^2h
Cancel out the pi immediately.
(1/3) * r^2 * h = 100
4r^2 = 300
r^2 = 75
r = sqrt 75
r = 5 * sqrt (3) units
The exact value can never be found as radius is irrational, but I'll give you the first few decimal digits.
r = 8.660 254 037 844 386 467 637 231 707 529 4
2007-06-04 23:43:39 · answer #3 · answered by Akilesh - Internet Undertaker 7 · 0⤊ 0⤋