Question

18. A hollow cylindrical metal pipe is 21 cm long. Its outer and inner diameters are 10 cm and
6 cm respectively. Find the total surface area of the metal used in making the pipe.​

Answer 1

Answer:

1156.58 cm^2

Step-by-step explanation:

TSA of Hollow cylinder = 2π (r1 + r2) (r2 - r1 + h)

                                       = 2 * 22/7 * ( 3 + 5) ( 2 + 21)

                                       = 2 * 22/7 * 8 * 23

                                       = 1156.58