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 

 

Answer 1

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`