Question

A tent is in the shape of a right circular cylinder up to a height of 3 m and conical above it. The total height of the tent is 13.5 m and the radius of its base is 14 m. Find the cost of cloth required to make the tent at the rate of Rs 80 per square metre. $[Take\pi =\frac{22}{7.}]$

Answer 1

CSA of cylinder $=2\pi rh$
$2\times \frac{22}{7}\times 14\times 3=264m^2$

radius = 14 m
height = 13.5 - 3 = 10.5

$l^2=r^2+h^2$

$14{}^2+10.5{}^{2}196+110.25=306.25l\sqrt{306.25}l=17.5m$

CSA of cone $=\pi rl$

$\frac{22}{7}\times 14\times 17.5=770m^2$

total area $=264+770=1034m^2$

cost of cloth per square m = Rs 80

cost of cloth $=1034m^2=80\times 1034=82720$