Q6 of 79 Page 229

The total surface area of a solid right circular cylinder is 1540 cm2. If the height is four times the radius of the base, then find the height of the cylinder.

Given : TSA of cylinder = 1540 cm2

To find : Height of cylinder = h = ?


Formula : TSA of cylinder = 2πr (h + r)


Solution : Let the radius and height of the cylinder be r and h respectively.


According to the given condition,


h = 4r


⇒ r =


TSA of cylinder = 2r (h + r)


⇒ 1540 = 2 × × (h + )


1540 =


h2 = = 28 × 28


⇒ h = 28 cm


∴ The height of the right circular cylinder is 8 cm.


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