I have started making a new file for a desktop organizer, based on one featured in FWW but with 3 dividers. I made a basic drawing in SketchUp after viewing the square one video (I subscribed to Square One.) about arcs. The video was extremely helpful. I made a comment after observing the video, and I know the answer to the questions I posed after making this basic drawing. I asked how to make a board with an arc and rectilinear parts. Tomorrow, I will start making the components and proceed. Now I’m having fun 
What exactly do you mean by this? Probably the easiest way to do what I think you are talking about is to draw a rectangle and then, on it, draw the arc and erase the unneeded edges. A lot like the way you would make the part in the shop.
Since I had drawn it out on paper first, I knew the measurements. I used the line tool, the two-point arc tool, and the push/pull tool.
That works, too. Many times new users have difficulty getting the arc drawn on plane with the rest of the edges. In that case there’s no face to extrude with Push/Pull. Since you were able to use Push/Pull you successfully created the face so onward and upward.
Yes. That’s a good start.
Thank you. I’m on my way. 