The inner and the outer radii of a cylindrical pipe are 5cm and 4cm respectively.Find the area of cross section of the pipe(Take pi=3.14).

Question

ganeshie8 · Answer

inner radius = 5
outer radius = 4

how can inner radius be greater than outer radius ? question looks wrong lol

anonymous · Answer

is it inner 4 ???

anonymous · Answer

I THINK ITS PRINTED WRONG!
inner=4 and outr=5

anonymous · Answer

plz. help anyone!

ganeshie8 · Answer

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ganeshie8 · Answer

it just the area of inside circle.
are of circle = $\pi r^2 = 3.14 * 4^2$

anonymous · Answer

pi(Routersquared- Routersquared)

anonymous · Answer

i got it!
pi(R sq. - R sq. )
= pi (R+r)* (R-r)
= 3.14* (5+4)*  (5-4)
= 3.14*20*1
= 62.80

ganeshie8 · Answer

hmm how u got that ?
cross section of pipe is just the inner circle area, right ?

it should be pi(r^2) = 3.14(4)(4) = 50.24