65PI=PI*5sqrt(25+h^2)
solve for height h
65/5= sqrt(25+h^2)
square both sides
169=25+h^2
h= 12
volume= 1/2 PI r^2 h
"Find the volume of a cone that has 5 as its base radius and a lateral surface area of 65 pi."
Help, thanks!
6 answers
Thanks!
But that's wrong :(
The lateral area is just πrs. Don't include the area of the base.
so,
πrs = 5πs = 65π, so s = 13
So, the height is 12, making the volume
v = πr^2 h = π*25*12 = 300π
so,
πrs = 5πs = 65π, so s = 13
So, the height is 12, making the volume
v = πr^2 h = π*25*12 = 300π
The answer is 100pi (bobpursley was right about the height but the formula he stated was incorrect)
the answer is 100pi
0 answers