Two triangles moving on a circle like on a carousel

I need to make scene where two triangles are moving around on a circle like on a carousel:

position1 = [ sin alpha, cos alpha]
position2 = [ -sin alpha, -cos alpha]

All that I have achieved is triangles merged together moving on one circle. How can I force independence of moves?

Perhaps you should offset alpha a bit in position2, not just change the sign of sine or cosine.

Thanks, I was thinking about this, but how I can do it?

Try setting position2 to -sin (alpha * 2.0), -cos (alpha * 2.0). Or any other value to multiply with.