Show ruler in Freeform app on iPad

I'm new to Freeform and was using to map an outdoor lighting plan for my patio. I don’t know what I did/touched, but a ruler showed up on the page (movable), diagonally across the left bottom corner. I didn’t want it at the time and I was able to delete it. However, now,I’d love to have it back to measure my distances. Anyone know how to get it back? Most of my searches say a ruler isn’t available…but I had it once (magically and inexplicably). Thanks.