Question

How many metres of cloth, $5$m wide, will be required to make a conical tent, the radius of whose base is $7$m and height is $24$m?

• A. $120$m
• B. $110$m
• C. $100$m
• D. $105$m

Answer 1

Answer: (D)

$105$m

Here the shape of tent is cone and the cloth will be a rectangle.

For making tent from the cloth the area of cloth will be same as the lateral surface area of the conical tent .

Area of rectangle $=length\times breadth$

Lateral surface Area of cone $=\pi \times Radius\times height$

So,

Area of cloth $=$ Lateral surface area of cone

$\Rightarrow length\times breadth=\pi \times Radius\times height$

$\Rightarrow length\times 5=\pi \times 7\times 24$

$\Rightarrow length\times 5=22\times 24$

$\Rightarrow length=105.6m$

So, the length will of cloth will be nearly $105m$.