Question

the height of the cylinder is 15 cm. the curved surface are is 660 square cm. find the radius?

Answer 1

Given:

• Height of cylinder = 15 cm
• Curved surface area = 660 cm²

To find out

Find the radius of cylinder?

Formula used:

Curved surface area of cylinder = 2πrh

Solution:

We know that,

Curved surface area of cylinder = 2πrh

660 = 2×22/7×r×15

660= 44/7×15×r

660/15=44/7×r

44= 44/7× r

44×7/44 = r

r=7

Knowledge Enhancer

• Curved surface area of cylinder = 2πrh
• Total surface area of cylinder = 2πr(h+r)
• Volume of cylinder = πr²h
• Each base surface area = π(R²-r²)

Answer 2

Given,

Height of the cylinder = 15cm

CSA of cylinder = 660cm²

To Find :

Radius of the Cylinder

Solution:

We know that,

CSA of a cylinder = 2πrh

=> 660 = 2πrh

=> 660 = 2 × 22/7 × r × 15

=> 660 = 44/7 × r × 15

=> 660 × 7 = 44 × 15 × r

=> 4620 = 660 × r

=> r = 4260/660

=> r = 7cm

Therefore, the radius of Cylinder is 7cm.