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Question
In the following figure, shows the cross-section of railway tunnel. The radius OA of the circular part is 2 m. If ∠AOB = 90°, calculate:
the perimeter of the cross-section
Solution
We have a cross section of a railway tunnel. `ΔOAB`is a right angled isosceles triangle, right angled at O. let OM be perpendicular to AB.
`"Perimeter of cross section is"`
= Major Are` AB+AB`
`=2(pi)(2)(3/4)+2sqrt2`
`=(3pi+2sqrt2)m`
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