How many square meters of tin will be used to make a 5 m long drainpipe with a diameter of 20 cm if 10%

How many square meters of tin will be used to make a 5 m long drainpipe with a diameter of 20 cm if 10% of the pipe surface area is added to the seams?

Find the pipe circumference, use the formula L = π * D:
L = π * 0.2 = 0.63 m.
Then the total surface area will be:
5 * 0.63 = 3.14 m ^ 2.
Add 10% to the seams:
3.14 + 3.14 * 10/100 = 3.45 m ^ 2.
Answer: the manufacture of the pipe will require 3.45 m ^ 2 of tin.