"Follow me" path with variable lenghts

[Bruno]

Hi guys,

I have a list of measurements that should be translated to two lines (indicated in red in the sketch)
So I would need the locations, relative to A, B, C, ... points and the length of that line.
(C has slightly different numbers)

I hope I've explained it well enough.
In the end, I will write a script that would draw these red lines based on the given numbers.

Thanks ahead for taking the time.
Even though I think the math is most likely not too complicated, this goes way over my head.

 

[Romsek]

are these red lines supposed to be parallel to the associated segment?

It's a bit tough to determine what controls the angle of the line containing the two calculated points from the drawing.

 

[markraz]

If I understand the problem (which I'm not sure I do) I think all you have to do is imagine circles at the points and then find points on the circles
you can use trig once you know theta and the radii (which you do). I already have a program that will do this, so if you need more help just let me know and I can try and find my code.

You could also just use parametric equations to solve this

 

[Dr.Peterson]

Hi guys,

I have a list of measurements that should be translated to two lines (indicated in red in the sketch)
So I would need the locations, relative to A, B, C, ... points and the length of that line.
(C has slightly different numbers)

I hope I've explained it well enough.
In the end, I will write a script that would draw these red lines based on the given numbers.

Thanks ahead for taking the time.
Even though I think the math is most likely not too complicated, this goes way over my head.

View attachment 24796

What determines the direction of the green lines?

 

[Bruno]

are these red lines supposed to be parallel to the associated segment?
It's a bit tough to determine what controls the angle of the line containing the two calculated points from the drawing.

The black lines are close to the center of a road and each 10m a stop point is introduced. The width of the road is measured from that point. If the line is exactly in the middle, the two red lines will be parallel.

I already have a program that will do this, so if you need more help just let me know and I can try and find my code.

I have no idea what language I will use. What have you used?

What determines the direction of the green lines?

My guess would be the exact center of the two black lines.

 

[Dr.Peterson]

My guess would be the exact center of the two black lines.

Does that mean the angle bisector? What about at points A and the other end?

Why is this only a guess? A well-defined problem needs clarity.

Are you just trying to approximate something in real life, which is not actually made of straight lines at all?

 

[Bruno]

It's indeed the angle bisector.
I'm trying to work out how a medieval cartographer could draw such correct maps with just a compass and measurement instruments. I'm sure much was artistic guesswork, but while investigating I thought it perhaps could be done mathematically.
I've drawn some measurements in Sketchup, but I can't figure out the math to code it.