Curve rotate fixed to specific angle

I am trying to write a script in GH, where I rotate a line by a given angle, but the end points of the resulting line, red and green dots must stay fixed to the orange line. I cannot figure this out , or what I a missing. thanks I imagine it’s rotate line , and extend length, but not sure what series of components it would take. Thanksl.!

I don’t understand what you want, at least draw the lines and try with Grasshopper (6.2 KB)