Question

The surface area of a sphere of radius 5 cm is stores the area of the curved surface area of cone of radius 4 cm .Find the height of the cone

Answer 1

4π(5)² = π(4)×l
(5)²= slant height = 25cm
radius = r = 4cm
r² + h² = l²
h² = l²-r²
h² = 609
h = √609 = 24.67 cm = height of the cone

Answer 2

Ar(sphere)=4πr²
CSA(cone)=πr(r+h)
CSA(cone)=Ar(sphere)
4πr²=πrl
4(25)=4l
25=l
l=25cm
By using Pythagoras theorem
l²=h²+r²
h²=l²-r²
h²=25²-4²
h²=625-16
h=√609
h=24.67cm
Hence the height of cone is 24.67cm.