Recently I've been working with a lot more projects that contain curved architectural features. It appears that I am unable to draw a line to an implied perpendicular point on an arc. I can draw a line to an implied point perpendicular to another line but not an arc. Please refer to attached images.
Image1 demonstrates the implied point perpendicular to a line.
Image2 demonstrates that there is no implied perpendiuclar point on the arc given by AutoCAD