Question

The volume and curved surface area of a cylindar are 1650cm3 and 660cm2 . find the radius and height of the cylindar

Answer 1

Given :-

• Volume of cylinder = 1650cm³.
• curved surface area of cylinder = 660cm².

To Find :-

• find the radius and height of the cylindar ?

Formula used :-

• Volume of cylinder = π * r² * h
• CSA of cylinder = 2 * π * r * h .

Solution :-

Let us assume that, radius & Height of cylinder are r & h respectively .

So,

→ π * r² * h = 1650

→ h = (1650) / (π * r²)

Putting value of h , in CSA now, we get,

→ 2 * π * r * [ (1650) / (π * r²) ] = 660

→ 2 * 1650 / r = 660

→ 3300 = 660r

→ r = (3300/660)

→ r = 5cm.

Putting value of r in in h = (1650) / (π * r²) now, we get,

→ h = (1650) / (π * 5²)

→ h = (66/π)

→ h = 66 * (7/22)

→ h = 3 * 7

→ h = 21cm.

Hence, The radius and the height of the cylinder are 5 cm & 21 cm Respectively.

Answer 2

Answer:

given volume=1650cm^3

CSA=660cm^2

let radius be r and height be h. so πr^2h=1650cm^3 and 2πrh=660cm^2

πrh=660÷2=330cm^2

r(πrh)=1650cm^3

r(330)=1650

r=1650÷330=5cm

we know 2πrh=660

therefore h=(660×7)/2×22×5=21cm