Length of metal pipe, l = 77 cm,

h = 77 cm.

Inner diameter = 4 cm,

∴ r_{1} = 2 cm.

Outer diameter= 4.4 cm.

∴ r_{2} = 2.2 cm.

(i) Inner surfce area of pipe (C.S.A) = 2πr_{1}h

= 2 × 22 × 2 × 11 = 968 cm^{2} .

(ii) Outer surface area of pipe (C.S.A) = 2πr_{2}h

= 2 × 22 × 2.2 × 11 = 44 × 24.2 = 1064.8 cm^{2} .

(iii) Total Surface area of Pipe (T.S.A.)

= Inner CSA + Outer CSA + Area of circular ring.

= 2πr_{1}h + 2πr_{2}h + (2πr_{2} 2h – 2πr_{1} 2h)

= 2032.8 + 5.28

∴ T.S.A. = 2038.08 cm^{2} .