Well.. okay, I found a work around but it's an exercise in geometry. I calculated a right triangle with one corner that was the angle I wanted and then drew two lines the required length each starting at a common vertex to make a 90 degree angle. Then I used the area tool to connect the 3 vertices and moved the resulting triangle to where I needed it, used the angle, and then deleted the area object. Phew.... so a measure tool or an angle tool would be good to have.
Oh yeah, and an "undo" button.