Question

The curved surface area of a cylinder is 8.8m2

.If the radius of the base of the cylinder is 0.7m then

find its height and total surface area.​

Answer 1

Given:

⇒R=0.7m

⇒CSA=4.4 m²

Let's assume height be x

⇒2πrh=4.4m²

$⇒2× \frac{22}{7} ×0.7x=4.4$

$⇒x= \frac{4.4 \times 7}{2 \times 22 \times 0.7} = 1m$

⇒Height=1metre

Answer 2

Given:

A cylinder with

• Curved surface area (CSA) = 8.8 m²
• Radius of base = 0.7 m

What To Find:

We have to find

• Height
• Total surface area (TSA)

How To Find:

To find the height, we have to take,

• CSA of cylinder = 2πrh

• Then, substitute the value and find height

To find the TSA, we have to take,

• TSA of cylinder = 2πr (h + r)

Solution:

• Finding the height of the cylinder.

Using the formula,

⇒ CSA = 2πrh

Substitute the values,

⇒ $\sf{8.8\:m^2 = 2 \times \dfrac{22}{7} \times 0.7 \times h}$

Cancel 7 and 0.7,

⇒ 8.8 m² = 2 × 22 × 0.1 × h

Multiply the numbers,

⇒ 8.8 m² = 0.44 × h

Take 0.44 to LHS,

⇒ $\sf{\dfrac{8.8}{0.44} = h}$

Divide 8.8 by 0.44,

⇒ 20 = h

∴ Thus, 20 m is the height of the cylinder.

• Finding the TSA of the cylinder.

Using the formula,

⇒ TSA = 2πr (h + r)

Substitute the value,

⇒ $\sf{TSA = 2 \times \dfrac{22}{7} \times 0.7 (20 + 0.7)}$

Solve the brackets,

⇒ $\sf{TSA = 2 \times \dfrac{22}{7} \times 0.7 \times 20.7}$

Cancel 7 and 0.7,

⇒ TSA = 2 × 22 × 0.1 × 20.7

Multiply the numbers,

⇒TSA = 91.08 m²

∴ Thus, the total surface area of cylinder is 91.08 m².