1)

The circumference of the base of a 10m high conical tent is 44 metres. Calculate the length of canvas used in making the tent , where the width of the canvas is 2m.


A) 132.2 m

B) 134.2 m

C) 130.6 m

D) 131.8 m

Answer:

Option B

Explanation:

Let r be the radius of the base,

Given $2\pi r=44$

$2\times \frac{22}{7}\times r=44$

$r=\frac{44\times 7}{2\times 22}=7 m$

Let the slant height = 1 m

$1=\sqrt{h^{2}+r^{2}}$

=$\sqrt{7^{2}+10^{2}}=12.2 m$

Surface Area = $\pi rl= \frac{22}{7}\times 7\times 12.2=268.4m^{2}$

Area canvas = 268.4 $m^{2}$,width=2 m

Lenght of canvas =$\frac{268.4}{2}=134.2 m$