A tent has a cylinder part of radius 3.5 m and height 3 m…

Step 1. The cylinder part. $2\pi r h = 2 \times \dfrac{22}{7} \times 3.5\ \text{m} \times 3\ \text{m} = 66\ \text{m}^2$.

Step 2. The cone. $\pi r l = \dfrac{22}{7} \times 3.5\ \text{m} \times 3.7\ \text{m} = 40.7\ \text{m}^2$.

Step 3. The canvas. $66\ \text{m}^2 + 40.7\ \text{m}^2 = 106.7\ \text{m}^2$.

Step 4. The strip. $106.7\ \text{m}^2 \div 2\ \text{m} = 53.35\ \text{m}$.