Problem:$($C$2)$

A circular curve $800m$ radius has been set out connecting two

straights with a deflection angle of $42.$ It is decided for

construction reasons, that the mid$-$point of the curve must be

moved $4m$ towards the centre, i$.$e away from the intersection

point. The alignment of the straights is to remain unaltered.

Calculate:

$($a$)$ the radius of the new curve,

$($b$)$ the distances from the intersection point to the

new tangents points,

$($c$)$ the deflection angles required for setting out $30$

$m$ chords of the new curve,

$($d$)$ the length of the final sub$-$chord.