A metal pipe is 77cm long.The …

A pipe will have two layers as shown in picture. There is a inner Cylinder and Outer Cylinder. Inner Radius = Inner Diameter / 2 = 4 / 2 = 2 cm = r Outer Radius = Outer Diameter / 2 = 4.4/2 = 2.2 cm = R Height of the pipe = 77 cm = h Inner Surface area of the Pipe = 2∏rh = 2×22×2×77/7 = 968 Square cm. Outer Surface area of the pipe = 2∏Rh = 2×22×2.2×77/7 = 1064.8 Square cm. Total Surface area = Inner Surface area + Outer Surface area + 2 × Cross section surface area. The cross section suface area is present at two ends of the pipe. This is the area covered between 2 circles. Total Surface area = Inner Surface area + Outer Surface area + 2 × Cross section surface area. = 968 + 1064.8 + 2×∏(R^2 – r^2) = 2032.8 + 2×22×(2.2×2.2 – 2×2)/7

A pipe will have two layers as shown in picture.  

There is a inner Cylinder and Outer Cylinder.

Inner Radius = Inner Diameter / 2 = 4 / 2 = 2 cm = r

Outer Radius = Outer Diameter / 2 = 4.4/2 = 2.2 cm = R

Height of the pipe = 77 cm = h

Inner Surface area of the Pipe = 2∏rh = 2×22×2×77/7 = 968 Square cm.

Outer Surface area of the pipe = 2∏Rh = 2×22×2.2×77/7 = 1064.8 Square cm.

Total Surface area = Inner Surface area + Outer Surface area + 2 × Cross section surface area.  

The cross section suface area is present at two ends of the pipe.  

This is the area covered between 2 circles.  

Total Surface area = Inner Surface area + Outer Surface area + 2 × Cross section surface area.  

= 968 + 1064.8 + 2×∏(R^2 – r^2)

= 2032.8 + 2×22×(2.2×2.2 – 2×2)/7

= 2032.8 + 5.28

= 2038.08 Square cm.