Would anyone be interested in having a function to draw an angle? I made a function for this that you can see here: https://github.com/AtsushiSakai/PythonRobotics/blob/master/ArmNavigation/two_joint_arm_to_point_control/Planar_Two_Link_IK.ipynb If this is something enough people are interested in, I can clean the code up and submit a PR for it.