Question

For a cylinder of radius 'r' and height 'h', TSA = and CSA = .

• A. 2πrh
• B. 2πrh + πr${}^2$
• C. 2πr(r+h)
• D. πr${}^2$

Answer 1

Answer: (A), (C)

The correct options are
A 2πrh
C 2πr(r+h)

A cylinder has 2 circular faces – one at the top and other at the bottom.
Therefore,
total surface area
= Curved surface area + sum of areas of 2 circular faces
$=2\pi rh+2\pi r^2$
$=2\pi r(r+h)$

CSA is the area of curved portion which is a rectangle of length 2πr and breadth h.
Therefore, CSA= 2πrh.