What length of tarpaulin 3 m wide will be required to make a conical tent of height 8 m and base radius 6 m?

h=8m, r=6m, l=√r² + h² = √6² + 8² = √100 = 10m
CSA = πrl = (3.14 × 6 × 10)m² = 188.4m²
Let the length of sheet required = x
Breadth = 3m
Area = l × b = 3 × x = 3x
20cm of length will be wasted:
Effective length = (x - 20/100) = 80x/100 m
CSA of tent = Area of sheet
188.4 = (80x/100)3
80x/100 = 62.8
x = 62.8 × 100/80
x = 78.5 m
Therefore, length required = 78.5 m ≈ 79 m