How to calculate a variable lenght on a bar?

[RCSen]

Hello.
I have a variable lengh on a bar due to a linear actuator, the triangle vector has 3 points (A B C), where A and C are blocked, B its the unknown position. How do you configure the script?, thank you so much and congratulations for the contribution.

[gabemorris12]

Hi,

It may be at the end of today or sometime tomorrow to when I can get around to it, but just to be clear, is this what you are describing?

The distance between A and B is the only thing that moves? If this isn't it, then you providing a diagram would help.

Thanks,
Gabe