Asking for advanced help with rotate tool

I’m trying to model a porch roof to save myself some math and hair pulling when it comes to making the real cuts. I have been using SU semi-professionally for about a year and am surprised to have run into such a basic question that is now holding up the project. Below is a simplified example of the problem I ran into. I would like to manipulate the blue component as shown, but have the bottom edge snap to the red object’s corner, not just visually close as using the rotate tool allows.

I will then use the trim tool and push/pull to make the “cuts” in my rafter (blue).

That’s actually a difficult operation to do using the built-in tools of SketchUp. However, Fredo6’s FredoScale extension has a Box Rotate version that can do it.

You’ll have to use a plugin or SketchUp’s own ‘Pie’ tool, one of the ‘arc’ tool options.

Use the ‘Pie’ tool with its center on the pivot, the first clicked point.
The second clicked point is the red snap corner
The third point is on the shown arc where it intersects the lower ‘edge to be snapped’. The inference before the third click should show a small red cross at this intersection.
Once you have drawn the pie you’ll be able to rotate the blue rafter over the arcs angle from where it is to the red corner.

All objects should be grouped separately, so the pie doesn’t stick to other geometry.


Animating what @Wo3Dan described: