I’m trying to find a way of creating a simple model of 4 connected lines (i.e. a quadrilateral) where I can alter the angle of one side and have the other sides adapt – i.e. linkages.

I have several ideas of how to calculate the appropriate corner points in a complicated manner (such as creating two arcs with relevant radii and then finding the intersection) but hoped there was something already available which could do this sort of thing. I have been unsuccessful in even finding a function where a point is positioned at set distances from two reference points.

Thanks.