Question

Find the radius of a cylinder which has a height of 7 cm and a curved surface area of 110 cm^2.

Answer 1

Answer:

Radius of the cylinder = 2.5 centimetres

Step-by-step explanation:

Given

Height of the cylinder = 7 centimetres

Curved surface area of the cylinder = 110cm²

The formula for curved surface area of a cylinder = 2πrh

According to the question,

2πrh = 110cm²

2 × 22/7 × r × 7 = 110cm      (π = 22/7)

44/7 × 7 × r = 110cm

44 × r = 110cm

r = 110/44

r = 5/2 centimetres

r = 2.5 centimetres

The radius of the cylinder is 2.5 centimetres

Answer 2

Answer:

• Radius of cylinder = 2.50 cm (Approx).

Step-by-step explanation:

Given:

• Height of cylinder = 7 cm
• CSA of cylinder = 110 cm²

To Find:

• Radius of cylinder

Now, we know that,

⇒ CSA of cylinder = 2πrh

⇒ 110 = 2 × 3.14 × r × 7

⇒ 110 = 6.28 × 7 × r

⇒ 110 = 43.96r

⇒ r = 110/43.96

⇒ r = 2.50 cm (Approx)

Hence, Radius of cylinder = 2.50 cm (Approx).