Question

find the total surface area of hollow cylinder with height 10cm and radii 3cm and 4cm​

Answer 1

Answer:

484 cm²

Step-by-step explanation:

As per given picture External radius = R = 4 cm

Internal radius =r = 3 cm

Height = 10 cm

Total surface area =2πRh + 2πrh + 2π(R² −r²  )

  = 2π [ Rh + rh + ((R² −r²  )]

  = 2 x 22/7 [ (4*10) + (3*10) + (4² - 3²)]

  = 44/7 [  40 + 30 + 16 - 9 ]

  = 44/7 (86 - 9)

  = $\frac{44}{7} * 77$

  = 44 x 11

  = 484 cm²