Geometry angles, Is there some way to lock the screen when a point is selected so only the angle or protractor will move?

When trying to complete the drawing angles in the geometry section it is very difficult on a mobile device. When I try to turn the protractor or drag a point to a given spot the entire screen moves. I know I am selecting the point bc the angle turns green and sometimes will move side to side but trying to move up or down is very difficult since the whole screen moves. Is there some way to lock the screen when a point is selected so only the angle or protractor will move?