Question

What is the approximate length in inches of the reverse curve section?

Answer 1

There are two circular models, one with radius 7 inches and another is radius 6.5 inches

Since the angles are in degrees, let us convert the angles from degree to radian.

`\begin{gathered} 45^o=(\pi)/(4) \\ 40^o=(2\pi)/(9) \end{gathered}`

the length of the curve section with radius 7 inches is

`\begin{gathered} A=(\pi)/(4)*7 \\ =5.497 \end{gathered}`

the length of the curve section with radius 6.5 inches is

`\begin{gathered} B=(2\pi)/(9)*6.5 \\ =4.538 \end{gathered}`

So, the total length is

`\begin{gathered} L=5.497+4.538 \\ =10.035 \\ \approx10.0\text{ (rounded off to the nearest tenth)} \end{gathered}`

Hence, the correct option is (c)