The angles in a pentagram have the same property: they all reduce to 9 (18, 36, 72, 108, 144).

On your diagram 3, 6 and 9 form an equilateral triangle which reminds the masonic triangle (nothing 'satanic' there.)

If you divide each number by 3, you have 1, 2 and 3. In ancient traditions 111 (1+1+1 = 3) and 123 (1+2+3 = 6) are numbers associated with the concept of pole and axis of the world (cosmic tree.)

In the tree of life of the kabbalah the triangle formed by Kether/AHH, Chokmah/IHVH and Binah/ELHIM has the values 111 and 123:
AHH+IHVH+ELHIM = 17+47+47 = 111
אלהים+יהוה+אהה (Ahah+Iahveh+Elohim) = 11+26+86 = 123

In the following Islamic figure, the cube and the pyramid (the link between earth and heaven) represent the axis and the letter Qaf (shaped like a 9) at the top, the pole.

Qaf is the first letter of the word Qutb which means pole. The first letter of the Arabic alphabet, Alif (equivalent of Hebraic Alef), has a the shape of a vertical axis and has a "polar" quality:
אלף (Alef) = 1+30+80 = 111
‫ا‬‫لف‬ (Alif) = 1+30+80 = 111
قطب (Qutb) = 100+9+2 = 111