As already said: there is no exact representation of the circle using Bezier curves.
To complete the other answers : for Bezier curve with n
segments the optimal distance to the control points, in the sense that the middle of the curve lies on the circle itself, is (4/3)*tan(pi/(2n))
.
![formula for n segments](https://i.stack.imgur.com/270te.png)
So for 4 points it is (4/3)*tan(pi/8) = 4*(sqrt(2)-1)/3 = 0.552284749831
.
![4 point case](https://i.stack.imgur.com/aEsuA.png)
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