Q2 of 79 Page 229

The total surface area of a solid right circular cylinder is 660 sq.cm. If its diameter of the base is 14 cm, find the height and curved surface area of the cylinder.

Given : Total surface area (TSA) of cylinder = 660 sq.cm.

Diameter of the base of the cylinder = d = 14 cm


To find : Height of cylinder = h = ?


Curved surface area (CSA) of cylinder = ?


Formula : d = 2r


TSA of cylinder = 2πr (h + r)


CSA of cylinder = 2πrh


Solution : diameter = d = 2r


⇒ Radius = r = = = 7 cm


TSA of cylinder = 2r (h + r)


⇒ 660 = 2 × × 7 (h + 7)


660 = 44 (h + 7)


44 (h + 7) = 660


⇒ h + 7 =


h + 7 = 15


⇒ h = 15 – 7


h = 8 cm


CSA of cylinder = 2rh = 2 × × 7 × 8


= 44 × 8 = 352 cm2


∴ The height of the right circular cylinder is 8 cm and its curved surface area is 352 cm2.


More from this chapter

All 79 →
1

A solid right circular cylinder has radius of 14 cm and height of 8 cm. Find its curved surface area and total surface area.

 3

Curved surface area and circumference at the base of a solid right circular cylinder are 4400 sq.cm and 110 cm respectively. Find its height and diameter.

 4

A mansion has 12 right cylindrical pillars each having radius 50 cm and height 3.5 m. Find the cost to paint the lateral surface of the pillars at Rs 20 per square metre.

 5

The total surface area of a solid right circular cylinder is 231 cm2. Its curved surface area is two thirds of the total surface area. Find the radius and height of the cylinder.