Question

The outer diameter of a metallic pipe is 18 cm and the thickness of the pipe is 2 cm and the height is 4 cm. Find the surface area of the metallic pipe

Answer 1

Answer:

Given outer diameter of metallic pipe

=

18

cm

(

R

)

outer radius

=

9

cm

Thickness

=

2

cm

Then inner radius

=

9

−

2

=

7

c

m

Height of pipe

=

4

cm

Pipe has a shape of cylinder then

Surface area of outer pipe

=

2

π

R

h

=

2

π

×

9

×

4

Outer area

=

72

π

c

m

2

Inner surface area of pipe

=

2

π

r

h

=

2

×

π

×

7

×

4

56

π

c

m

2

Now surface area of metallic pipe

=

72

π

−

56

π

Area

=

16

π

c

m

2

∴

Surface area of metallic pipe is

16

π

c

m

2