Let me be more precise... Pls refer to the image diagram attached along this post..

You will find 5 points.. I need to calculate points a, b, c and d.. SO i thought i would begin by finding points a, d

lengths (Pa) and (Pd) is not constant.. it may vary every time.. it is called "along boundary length".. So, for a given along boundary length, i need to find these two points a, and d, with respect to P in such a way that,

Code:

l(Pa) = l(Pd) = along boundary length

and points a and d must lie on any of the line segments..

First way i thought was to find the tangent(shown in green), of "along boundary length" and get two end points.. from these two end points i can draw a line which will intersect the arc, and i can get values of "a" and "d"... But now i feel this logic is having some fault..

Now am stuck up.. My ultimate goal is to find values of points a, b, c and d for given set of inputs:

1. Point P

2. along boundary length l(Pa), l(Pd)

3. off boundary length l(ab), l(cd)

Any way to get this solved..??

Thanks in advance