It often helps to approach building a model in SketchUp as you would building in the real world.
And as a new user, you’ll become far more proficient with SketchUp by learning the full potential of its native tools before resorting to unnecessary plugins.
So, how would one position the brace board properly to mark it for the cuts?
Most likely you’d place the top edge of the lower end in position and rotate the board about that point until the lower edge of the upper end is in position.
One can easily do the same with SketchUp’s native tools.
Click through the Scenes in this tutorial model:
Brace Modeling Tutorial.skp (211.1 KB)
Key to the process: Understanding the power of Inferencing and use of the Arc Tool … 