Question

About how much cardboard is needed to make the inner tube for a roll of paper if the tube has a radius of 2.25 cm and is 24 cm long?
382 cm
339 cm?
679 cm
371 cm

Answer 1

Step-by-step explanation:

Cardboard needed to make tube =

Circumference of Circle base (remember the base is hollow therefore there is no area needed.) x Length of Tube

given r = 2.25cm

L = 24cm

Cardboard needed =

$2\pi \: rl = \\ 2\pi(2.25)(24) \\ = 2\pi(54) \\ = 108\pi {cm}^{2} \\ = 339 {cm}^{2}$