The amount of cardboard needed is 1360cm² . The amount of metal needed is 244.92 cm² . The amount of paper needed for the Curved part is 188.4 cm²
A.)
Surface area of a box = 2(lw + lh + wh)
Now we have :
2[(20×4) + (25 × 4) + (20 × 25)]
2[80 + 100 + 500]
2[680]
= 1360 cm²
The amount of cardboard used is 1360 cm²
B.)
surface area of a cylinder = 2πrh + 2πr²
- diameter = 6 ; radius = 6/2 = 3cm
(2×π×3×10) + (2×π×3²)
188.4 + 56.52
= 244.92 cm²
ii.)
The curved surface area of cylinder : 2πrh
Curved surface Area = 2 × π × 3 × 10
Curved surface area = 188.4 cm²