What length of tarpaulin 3 m wide will be required to make conical tent of height 8 m and base radius 6 m? Assume that the extra length of material that will be required for stitching margins and wastage in cutting is approximately 20 cm (Use π = 3.14)
The diagram is given as:
Height (h) = 8m
Radius (r) = 6m
Now, we know that,
According to Pythagoras theorem, l2 = r2 + h2
⇒ l2 = 62 + 82
⇒ l2 = (62 + 82)
⇒ l2 = 36 + 64
⇒ l2 = 100
⇒ l = √100 = 10 m
CSA of conical tent = πrl
= π × 6m × 10 m
= 22/7 × 6m × 10 m
= 188.57 m2
≈ 186 m2
Now, Let the length of tarpaulin sheet required be "x" m
As 20 cm will be wasted, therefore, the effective length will be = (x − 20 cm) = (x − 0.2 m)
Breadth of tarpaulin = 3 m
Area of sheet = CSA of tent
⇒ [(x − 0.2 m) × 3] m = 188.4 m2
⇒ x − 0.2 m = 62.8 m
⇒x = 63 m
Therefore, the length of the required tarpaulin sheet will be 63 m