hi bobbym and BeamReacher,

Firstly, I agree with MrWhy. There are too many variables to correctly determine the nature of the curve. But let's assume it is part of a circle.

In my diagram, I've converted the distances to feet.

The following equations apply:

From these last two

I used trial and improvement to find a = 0.03370775.... radians.

This gives the radius as

From the top two equations

Using the value of R and the quadratic formula

d = 44.498509.....

(My earlier answer of 63 was because I had used 2641 rather than 2640.5 for the arc length.)

Bob