Tile wall edge trim

[EdDesign]

I'm trying to trim out a simple shower tub enclosure with 1/4 rnd trim with mitered corner where the vertical edge meet the horizontal edge. Is there a method in the molding dialogs

for doing this? Where or how do I draw a molding line that is vertical? Obviously I've missed something very basic. Help greatly appreciated.  Ed Spena  X7 Premium.