Sorry for asking about very beginner question. But I have no idea how to solve it.

I am modeling a round stool look like this.

[![enter image description here][1]][1]

When I built one of leg, I don't have idea how to copy another one perfectly. 
[![enter image description here][2]][2]

I tried to use mirror modifier. But it can not save the details of connection.

[![enter image description here][3]][3]

Is there any easy way to duplicate and paste to the correct part?
I only can think that delete the stool leg part one by one and paste it 3 times...

Thanks for helping!


  [1]: https://i.sstatic.net/VjoRg.png
  [2]: https://i.sstatic.net/DlnMO.png
  [3]: https://i.sstatic.net/6mutm.png