DIY Ring construction

[YurterRT]

This will surely be the greenest post ever I'm sure 😄
I am in the beginning stage of planning to build custom yurt. Hopin to use materials on hand to serve each facet of yurt .
Is it reasonable to construct ring using landscape timbers ?
Figuring angle cuts , would it be better to use 6 timbers or 12 timbers .
I've read these awesome posts in threads and am inspired to meet my self applied challenge. I'm putting together a yurt to use in a dog park /camp site for some community children & their canine buddy's.
I'm green on terms , it measures 15' from center to outside.
I want to meet this challenge so I have no pride to hurt on my ignorance. Im out to learn and get this quality yurt in existence for these kids ( I'm 60 and got plenty of kid, common sense, ability to learn , backed by hard headed beds when needed to be tenacious to the end .
So startin with the ring - help please. 😄