Question

The internal and external radius of a metallic
cylinder are 3 cm and 3.5 cm respectively. If the
length of the pipe is 56 cm, find its total surface
area (Use t = 3.14).​

Answer 1

Answer:

1251.29Cm Square

Step-by-step explanation:

$r1 = 3cm \\ r2 = 3.5cm \\h = 56cm \\ = 2\pi \: (r2)h + 2\pi {(r2)}^{2} + 2\pi \: {(r1)}^{2} \\ = 2\pi(3.5)(56) + 2\pi {(3.5)}^{2} + 2\pi {(3)}^{2} \\ = 2\pi(196) + 2\pi(12.25) - 2\pi(9) \\ = 2\pi(196 + 3.25) \\ = 2\pi(199.25) \\ = 2 \times 3.14 \times 199.25 \\ = 1251.29 {cm}^{2}$