How to find the proportion of painting?

Use scale and cad to solve this problem.

1. First open the operation interface of cad, as shown below.

2. Draw a rectangle 600 mm long and 200 mm wide. There are many ways to draw a rectangle, such as entering the command l or rec.

3. Enter the zoom command sc, and then press Enter.

4. At this point, cad will prompt you to select a rectangle and press enter. At this point, it's time to set the base point.

5. Select the rectangular vertex in the lower left corner as the base point. Then enter the scale of 0.5, that is, the whole figure is reduced by half (including length and width).

6. Next, you will see the scaled rendering. If you measure it again and find that the result is the same as that of scaling by 0.5, then you have succeeded.