Question

The height of a tent is $9$ m. It's base diameter is $24$ m. What is its slant height. Find the approximate cost of canvas cloth required if it costs Rs. $14$ per sq. m.

Answer 1

Given the base diameter of tent is $d=24$ m and height of a tent is $h=9$ m and the cost of canvas cloth is Rs. $14$ per sq m.

Let slant height of tent be $l$, then

$l^2=r^2+h^2\Rightarrow l=\sqrt{{\left(12\right)}^2+{\left(9\right)}^2}=\sqrt{225}=15m$.

Therefore, Area of canvas required $=$ Curved surface area of the cone

$=\pi rl=\frac{22}{7}\times 12\times 15=\frac{3960}{7}$

Then, Cost of canvas $=Rs.(\frac{3960}{7}\times 14)=Rs.7920$.