Question

A metal pipe is 77 cm long the inner diameter of the cross section is 4 cm and the outer diameter is 4.8 cm find the (i) inner curved surface area (ii) outer curved surface area (iii) total surface area

Answer with full step by step explaination​

Answer 1

Explanation:

outer area=

first need to find the circumference of outer diameter

= π×4.8

= 15.079644.... cm

to find the outer curved area you would then do

= 77×15.079644

(ii) =1161.13264 cm²

inner curve area

circumference= π×4

=12.5663706.... cm

77×12.5663706

(i) =967.610537 cm²

total surface area=

as the outer and inner curved areas are already found only the top and bottom surfaces need to be

= area of larger circle

=π×4.8²

=72.382294.... cm²

smaller circle

=π×4²

=50.2654824.... cm²

72.382...-50.265

=22.1168116 x 2

=44.2336232 cm²

total surface area

(iii)= 2172.9768 cm²

(round this to however many decimals you need)

I hope this is understandable and useful!

also how many marks is this for?