This is such a newbie question, I almost can't understand why I can't work this out!
I'm trying to sketch on the side of a revolved cylinder shape, but the shape has a taper.
I successfully managed to insert a reference plane on another section using the exact same method, and it worked perfectly fine.
However this time when I insert my plane with the same references the preview appears with the plane at an angle. (as shown below)
Can someone explain why this happens? Or how I can get the plane to sit perfectly at the desired 90 degree angle?