Question

aright circular cylinder just encloses a sphere of radius 20cm. find ratio of the sphere's surface area to cylinder's CSA

Answer 1

Given :-

Radius of Sphere(r) = 20cm

To find :-

Ratio of the spheres surface area to cylinders CSA.

We know That :-

FORMULA -

Surface Area of A sphere = 4πr²

4πr² = 4 × π × 20 × 20 ---1

CSA of Cylinder = 2πr

2πr = 2 × π × 20 ---2

Solution :-

Ratio of the spheres surface area to cylinders CSA = 1/2

By substituting 1 & 2 values we get

4 × π × 20 × 20.

------------------------ = 2 × 20 = 40

2 × π × 20