Question

A metal pipe is 77 cm long, the inner diameter of the cross- section is 4 cm and Outer diameter is 4.8 CM.Find the (a)inner curved surface area , (b)outer curved surface area and (c)and total surface area ​?

Answer given on back of the book is (a) 968cm square ,
(b) 1161.6cm square
(c) 2140.66cm square

Answer 1

AnswEr :-

Height of the Pipe = 77cm

Inner Diameter = 4cm

Outer Diameter = 4.8 cm

Inner radius = 2cm

Outer radius = 2.4cm

Inner Curved surface area = Outer Curved surface area = 2πrh

=> 2 × 22/7 × 2 ×77

=> 968 Square cm

Outer curved Surface area = 2πrh

=> 2 × 22/7× 2.4 × 77

=> 1161.6 Square cm

Total surface area = outer Curved surface area + inner curved surface area

=> 968 + 1161.6 = 2129.6 square cm