Question

a sphere , a cylinder andnd a cone are of the same radius and same height . find the ratio of their curved surface areas?​

Answer 1

Answer:

Hello mate...

Since, the height of a sphere is the diameter, the cone and cylinder have height 2r.

Then

Curved surface area of Sphere= 4πr²

Curved surface area of cylinder = 2πr(2r) = 4πr²

Curved surface area of cone = πrl

where, l = √(r2 + h2 ) = √( r2 + (2r)2) = √(5r2) = r√5

⇒ Curved surface area of cone = π√5r2

Now,

Ratio of CSA 's a sphere ,cylinder and a cone = 4πr2:2πrh : πrl

= 4πr2:4πr2 : πr2√5

= 4 : 4 : √5

Answer 2

Step-by-step explanation:

• csa of

sphere =4πr2

csa of cylinder = 2πrh

=2πr(2r)

4πr2

csa of cone= πrl

l=√(2r)2+r2

=√5r2

=r√5

csa of cone =πr(√5r) =πr2(√5)

• csa of sphere: csa of cylinder : csa of cone
• 4πr2:4πr2:πr2√5
• 4:4√5

hope it helpgul , thank you