Question

Spear a cylinder and a cone have same base and height is equal to diameter of sphere then ratio between their curved surface area is​

Answer 1

Answer:

Step-by-step explanation:

9th

Maths

Surface Areas and Volumes

Surface Area of Right Circular Cylinders and Cones

A sphere, a cylinder and a ...

MATHS

avatar

Asked on December 26, 2019 by

Prabhjit Sehgal

A sphere, a cylinder and a cone are of the same radius and same height. Find the ratio of their curved surfaces.

HARD

Help best friend

Study later

ANSWER

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=

(r

2

+h

2

​

)=

(r2+(2r)

2

​

)=

5r

2

​

=r

5

​

⇒ Curved surface area of cone =π

5r

2

​

Now,

ratio of CSA 's a sphere ,cylinder and a cone = 4πr

2

:2πrh:πrl

=4πr

2

:4πr

2

:πr

2

5

​

=4:4:

5

​

Follow me