Question

if the lateral surface area of a cylinder is 440cm2 and it's height is 5cm then find radius of base and it's value​

Answer 1

✬ Radius = 14 cm ✬

Step-by-step explanation:

Given:

• Lateral surface area of cylinder is 440 cm².
• Measure of height of cylinder is 5 cm.

To Find:

• What is the measure of radius ?

Solution: Let the radius of base of cylinder be r cm.

As we know that

★ LSA of Cylinder = 2πrh ★

A/q

• Lsa is 440 cm²

$\implies{\rm }$ 2πrh = 440

$\implies{\rm }$ 2(22/7)(r)(5) = 440

$\implies{\rm }$ 44/7(5r) = 440

$\implies{\rm }$ 220r/7 = 440

$\implies{\rm }$ 220r = 440(7)

$\implies{\rm }$ 220r = 3080

$\implies{\rm }$ r = 3080/220

$\implies{\rm }$ r = 14

Hence, Radius of base of cylinder is 14 cm.

_____________

★ Verification ★

➙ 440 = 2(22/7)(14)(5)

➙ 440 = 44/7(70)

➙ 440 = 44(10)

➙ 440 = 440

$\large\boxed{\texttt{Verified}}$

Answer 2

$\sf\underline\green{Given:-}$

• Lateral surface of a cylinder (LSA) =440 cm².

• Height of the cylinder ( h) =5 cm

$\sf\underline\green{To \: Find:-}$

• The radius of the cylinder.

$\sf\underline\green{Solution:-}$

Let, the radius of the cylinder = r cm.

We know,

The lateral surface area of the cylinder (LSA) $\sf{ = 2\pi rh}$

By condition,

$\sf{ 2\pi rh = 440}$

$\sf{\implies 2 \times \frac{22}{7} \times r \times 5 = 440 }$

$\sf{\implies \frac{44}{7} \times 5r = 440 }$

$\sf{\implies \frac{220}{7}r = 440 }$

$\sf{\implies 220r = 440 \times 7}$

$\sf{\implies 220r = 3080 }$

$\sf{\implies r = \cancel\frac{3080}{220} }$

$\sf{\implies \: r = 14 \: cm}$

$\rule{300}{2}$

$\sf\underline\green{Hence, \: the \: radius \:of \: the \: cylinder \: is \: 14 \: cm.}$