Let k(n) denote the minimum number of iterations deeded to make sure that every polygon with n side becomes convex after at most n midpoint iterations.
It is clear that:
![[Graphics:../Images/index_gr_21.gif]](../Images/index_gr_21.gif)
Further, it is not hard to see that
![[Graphics:../Images/index_gr_22.gif]](../Images/index_gr_22.gif)
which we may check as follows:
![[Graphics:../Images/index_gr_23.gif]](../Images/index_gr_23.gif)
To get an idea as to what is the probablity that a random 4-gon is convex:
![[Graphics:../Images/index_gr_25.gif]](../Images/index_gr_25.gif)
So this seems to suggest that a random 4-gon is convex about 30% of the time.
![[Graphics:../Images/index_gr_28.gif]](../Images/index_gr_28.gif)
![[Graphics:../Images/index_gr_29.gif]](../Images/index_gr_29.gif)
![[Graphics:../Images/index_gr_31.gif]](../Images/index_gr_31.gif)
![[Graphics:../Images/index_gr_33.gif]](../Images/index_gr_33.gif)
![[Graphics:../Images/index_gr_34.gif]](../Images/index_gr_34.gif)
![[Graphics:../Images/index_gr_36.gif]](../Images/index_gr_36.gif)
![[Graphics:../Images/index_gr_37.gif]](../Images/index_gr_37.gif)
![[Graphics:../Images/index_gr_39.gif]](../Images/index_gr_39.gif)
![[Graphics:../Images/index_gr_41.gif]](../Images/index_gr_41.gif)