James Black wrote:
Where can I find mitre angles for creating a circular border around
the base of trees? For example, what is the angle cut needed to
create a 7 foot circle, an 8 foot, or 9 foot circle?

Thanks.

This isn't what you're asking, but aren't railroad ties treated with
all sorts of nasty wood-preserving chemicals, chemicals that can leach
into the ground water?

Patrick