Question

the volume of space inside a right circular conical tent is 2200/7m sq.And its vertical height is 12m.Find the canvas required to make the tent and also find the cost of the canvas at theRS.120m sq. (assume pi value 22/7)

Answer 1

$\begin{array}{l}\text{Given, the volume of the conical cone is}\frac{2200}{7}{m}^3,\text{and h=12}\\ \text{we know that the volume of the cone is}\frac{1}{3}\pi r^{2}h,\\ \therefore \frac{1}{3}\pi r^{2}h=\frac{2200}{7}\\ =>\frac{1}{3}\times \frac{22}{7}{r}^2\times 12=\frac{2200}{7}\\ =>4r^2=100\\ =>r=5\\ \therefore \text{slant height is,}\\ =>l=\sqrt{r^2+h^2}\\ =>l=\sqrt{25+144}\\ =>l=\sqrt{169}\\ =>l=13\\ \therefore \text{curve surface area=}\pi \text{rl=}\frac{22}{7}\times 5\times 13=204.1m^2\\ \therefore \text{total cost is=}204.1\times 120=\text{Rs}\text{.24492}\end{array}$