Calling rotation rotation if possible from handle icon like in video, and right click menu rotate, and rotate from icon from top bar.
Angle could be specified in a text label at bottom of screen, but more interactive mouse/keyboard oriented rotation must be available.
Holding Shift or Ctrl on keyboard to activate free mode, while 90 snap mode is default, rotation should be centered in the shape center, and use mouse to rotate interactively.
shapes should align to be parallel when brought close with the mouse.
Shapes should align at intersection, please look at video to understand practicality of these alignments