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The circumference of the base of a 10 m height conical tent is 44 metres. Calculate the length of canvas used in making the tent if width of canvas is 2 m. (Use π=22/7).
Circumference of circular base of cone = 2πr = 44 m
Height (h )= 10 m
= 2××r = 44 = r = 7m
Slant height (l ) = √(102+72) = √149 = 12.20 m
Curved surface area of tent = πrl = 22/7 ×7×12.20 = 268.4 m2
Hence, length of 2m wide canvas needed = 268.4/2 = 134.2 m
A bus stop is barricaded from the remaining part of the road, by using 50 hollow cone made of recycled card-board. Each cone has a base diameter of 40 cm and height 1 m. If the outer side of each of the cones is to be painted and the cost of painting is Rs. 12 per m2. What will be the cost of painting all these cones. (Use π=3.14 and = 1.02).