A case study of AutoCAD plane graphic problem

Yesterday, the floor plan practice set (advanced type) 140P finished. In the course of doing, 127 problems have not been done. Depressed for a long time. I finally found the answer yesterday. I'll post the process now. Oh. (I am a beginner yo, master to throw bricks after looking, pick up a little bit ah, thank you!!!) ）

(in addition, say, this practice is the master of my advice to teach, not my solution, hehe.) ）

First look at the question:

Solution: (animation compared to the consumption of resources if it causes a pause recommended to close other applications and then view)