There should be a ruler available in ActivInspire that can be accessed by going to the upper left of the screen and selecting Tools>Math Tools>Ruler. It will then populate in your flipchart.
If it shows in millimeters then you can change it to centimeters by clicking in the middle of the ruler to make 3 small dots appear. Click those dots then select Top or Bottom Scale (depending on if you would like the cm listed on the top or the bottom of the ruler) and then select cm.
You may also add the ruler to your Toolbox by going to File>Settings>Commands then selecting Ruler from the list on the left, clicking the Add button at the bottom then Done.
If you have any questions then please don’t hesitate to contact us.