Question

If the CSA of a cylinder is 3168 sqcm and it's height is 21cm than its diameter is?

Answer 1

GIVEN:

• CSA of Cylinder = 3168 cm²
• Height of the cylinder = 21 cm

TO FIND:

• What is the diameter of the cylinder ?

SOLUTION:

Let the radius of the cylinder be 'r' cm

To find the CSA of the cylinder, we use the formula:-

❰ C.S.A. = 2πrh ❱

According to question:-

On putting the given values in the formula, we get

➠ 3168 = 2 $\times$$\sf{\dfrac{22}{7}}$$\times$ r $\times$ 21

➠ 3168 = 2 $\times$ 22 $\times$ r $\times$ 3

➠ 3168 = 132r

➠ $\sf{\cancel\dfrac{3168}{132}}$ = r

❬ radius = 24 cm ❭

【Diameter = 2 $\times$ r】

✒ Diameter = 2 $\times$ 24

✒ Diameter = 48 cm

❝ Hence, the diameter of the cylinder is 48 cm ❞

______________________

Answer 2

Qᴜᴇsᴛɪᴏɴ :

➥ If the CSA of a cylinder is 3168 cm² and it's height is 21cm than its diameter is?

Aɴsᴡᴇʀ :

➥ The diameter of cylinder = 48 cm

Gɪᴠᴇɴ :

➤ CSA of the cylinder = 3168 cm²

➤ Height of the cylinder = 21 cm

Tᴏ Fɪɴᴅ :

➤ The diameter of the cylinder = ?

Sᴏʟᴜᴛɪᴏɴ :

We know that,

CSA of the cylinder = 2πrh

$:\implies$ 3168 = 2 × $\sf{\dfrac{22}{7}}$ × r × 21

$:\implies$ 3168 = 2 × 22 × r × 3

$:\implies$ 3168 = 132r

$:\implies$ r = $\sf{\dfrac{3168}{132}}$

$:\implies$ $\underline{\overline{\boxed{\green{\bf{\:\:r = 24\:cm\:\:}}}}}$

Now,

Diameter = 2 × r

☛ On putting values

$:\implies$ Diameter = 2 × 24

$:\implies$ $\underline{\overline{\boxed{\purple{\bf{\:\:Diameter = 48\:cm\:\:}}}}}$

Hence, the diameter of the cylinder is 48 cm.