August 3, 2018October 19, 2018 by Tiana Evelyn K’Nex Toys The basic triangle that starts the construction. Three basic triangles will combine to make the first stage of Sierpinski triangle. First stage. Three first stage triangles combine to make a second stage triangle. Three second stage triangles combine to make a third stage. Mathematicians building the third stage. Check - is this a third stage triangle? Starting to combine 3rd stage triangles into the 4th stage. The 4th stage is almost done! The thrill of victory - success in constructing a 4th stage Sierpinski triangle!