BIO RAD ZE5 User Manual page 233

To add a polygon region to a plot
1. In the plot and histogram toolbar, click Add Polygon Region.
2. Click inside the plot where you want the first corner of the polygon.
3. Move the pointer and click again to create more corners of the polygon.
4. Double-click to finish drawing the polygon.
5. To move the polygon to another part of the plot, point inside the region.
Using Plot and Histogram Tools
User Guide | 231