Question

find the correct answer with explanation.. answer fast ..

Answer 1

Given h = 77cm.

Given Inner Diameter of the cross-section d = 4cm.

Then the radius r = 4/2

                              = 2cm.


Given that Outer Diameter of the cross-section d = 4.4cm.

Then the radius R = 4.4/2

                               = 2.2cm.



(1)  Inner curved surface area:

= 2pirh

= 2 * 22/7 * 2 * 77

= 2 * 22 * 11/7

= 968cm^2.



(2) Outer curved surface area:

= 2piRh

= 2 * 22/7 * 2.2 * 77

= 1064.8cm^2



(3) Total surface area:

= 2pirh + 2piRh + 2pi(R^2 - r^2)

= 968 + 1064.8 + 2 * 22/7((2.2)^2 - (2)^2)

= 968 + 1064.8 + 2 * 22/7(4.84 - 4)

= 2032.8 + 2 * 22/7(0.84)

= 2032.8 + 2 * 22 * 0.12

= 2032.8 + 5.28

= 2038.08cm^2.


Hope this helps!