This page gives step-by-step assembly instructions for the 12-stick puzzle
Start with the twelve sticks, three in each of four colors.
Each has two notches near the middle and a third notch at one end.
Using the end notch in a consistent cyclic manner, make a triangle and
start a second triangle.
Small rubber bands can hold the parts together temporarily.
Link the first two triangles like a chain before completing the second
Push the two triangles together, as shown at left. Make two sides
of the third triangle, as shown at right.
Insert the partial third triangle so it mates with notches of the first
Complete the third triangle by weaving in its third edge and rubber
Add the three sticks of the fourth triangle one at a time.
The previous joints will open slightly as each stick is added; then
close them up.
Rubber bands will not be needed for the fourth triangle.
Push everything together, make sure all eight three-fold joints are
tight, and remove the rubber bands.