Question

THE TOTAL SURFACE AREA OF HALLOW CYLINDER OPEN AT BOTH ENDS. IF THE LENGHT IS 12 CM THE EXTERNAL DIAMEMETER 10 CM AND THICKNESS IS 2CM.​

Answer 1

Let outer radius be r2 and inner radius=r1, height be h

So total surface area=2*pi*h*(r2+r1) + 2*pi* (r2^2 -r1^2)

Since h=22cm, r2=7cm,r1=7–1=6cm

So total surface area=2*(22/7)*22*(13) + 2*(22/7)*(49–36)

=44*(13/7)*(23)

=1879.43cm^2