Question

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

Answer 1

Given $r=7mh=24m$

Slant height $l=\sqrt{r^2+h^2}$

$=\sqrt{49+576}$

$=\sqrt{625}$

$=25m$

CSA of the cone $=\pi rl$

$=\frac{22}{7}\times 7\times 25$

$=550m^2$

Length of the cloth used $=\frac{Area}{Width}$

$=\frac{550}{5}$

$=110m$