Win 7, Sketchup 17.2.2555 *(it should not really matter)*

I want to model the front roof section of a trailer, but I really don’t have a clue on how to get started.

Imagine there is an arc on the YZ plane. The arc starts at (0,0,0) and goes to (0,100,0). The peak is at (0,50,10). Thickness is add to the arc and it is pulled in the positive X direction for 10 so that the endpoints of the arc are now (10,0,0) and (10,100,0)

The arc is now rotated through the axis of those two endpoints. As the arc is rotated 90°, the peak of the arc goes to zero. There will be some projection ahead of the axis of rotation.

This is the best I can describe what I want. **How would you start after placing the arc on the on the YZ plane ?**