How can I view the plane perpendicularly and draw on it as show in the image below?
Thanks very much in advance.
Click on “Pespective” in the upper left corner of the viewport and select view. For more information see Help about viewports and Cplanes.
I think the new Auto CPlane tool in Rhino 8 can do that.
After the CPlane is set, run the Plan command to set the view perpendicular.