In a conical tent, a person is standing at the circumference of the base. The angle of elevation of vertex of the tent is 60° and its height is 50 m. Find the cost of material used to make the tent at the rate of ₨. 16.5/meter. (Use \(\pi\) = 3.14)
Answer & explanation
Correct answer: option 4
CSA = \(\pi\)rl
tan 60° = \(\sqrt{3}\) : 1
(AB) (BC)
↓
60 ↓
\(\frac{60}{\sqrt{3}}\) = 20\(\sqrt{3}\)
sin 60° = \(\sqrt{3}\) : 2
(AB) (AC)
↓
60 ↓
2 x \(\frac{60}{\sqrt{3}}\) = 40\(\sqrt{3}\)
CSA = \(\pi\)rl = \(\pi\) x 20\(\sqrt{3}\) X 40\(\sqrt{3}\) = 7536
Cost of the material = 7536 x 16.5 = ₨. 124344