Question

How to do this Surface area and volume question? Please help me. I will mark you as brainliest

Answer 1

heya mate...

here is your answer...

Given :

CSA of cylindrical pillar is 264 m²

Volume of the cylindrical pillar is 924 m³

To be found,

Diameter and the height of the pillar.

Let the radius be r and height be h.

CSA of the pillar = 2πrh

=> 264 = 2 × 22/7 × r × h

=> 264 = 44/7 × rh

=> 264 × 7/44 = rh

=> 42 = rh ______(i)

Now,

Volume of the cylindrical pillar = πr²h

=> 924 = 22/7 × r × r × h

=> 924 × 7/22 = × r × r × h

=> 294 = r × r × h

=> 294 = r × 42

[ as from equation (i) we get rh = 42 ]

=> 249/42= r

=> 7 = r

Therefore, radius (r) is 7 m.

And from equation (i),

=> 42 = rh

=> 42 = 7 × h

=> 42/7= h

=> 6 = h

Therefore, height (h) is 6m.

Hence,

Diameter = 2 × radius = 2 × 7 = 14 m

and height = 6