Procedures:

1) Assembly of 20 equilateral triangles:

In order to assemble the triangles, you must check if the straws are straight or articulated. If they are articulated ones, vertices will be formed by straw articulation (Figure 1 and 2).

2) Assembly of 20 equilateral triangles:

• 2.1) Straight Straws:
• Out of 44 straws, cut 30 straws of the same color in 10 cm-pieces (60 pieces) and keep the surplus to use later for side or vertex fittings of the 20 triangles. Use 7 additional straws, preferably of the same color as the other 30 straws, to be cut and to form fittings or remaining vertices (figures 3, 4 and 5);
• Use the 10cm-pieces of straw, in groups of 3, to form the sides of the triangles, and use the surplus, in groups of three, from the 30 and 7 straws that were cut to assemble fittings or side vertices (figure 6);
• The use of these pieces to form vertices or fittings must follow the instruction below (figure 7, 8 and 9);
• Fold them vertically (longitudinally);
• Fold them on half horizontally (transversally);
• Insert them, until half the way, through the holes in each side that form the vertex;
• Reinforce these vertices with adhesive tape (figure 10).

• 2.2)Articulated Straws:
• Out of 64 straws, cut 40 straws of the same color in a way the long straight parts measure 9 cm and the short straight parts measure 4.5 cm (figure 3, 4, 5, 6 and 7);
• Cut 20 straws in a way each side of the articulation measures 3 cm of straight parts and keep the surplus to use later in dinucleotides; (figures 10 and 11);
• All vertices are articulated;
• Use the 20 pieces cut by half and the articulations of 20 straws to close the triangle, forming one of the sides (4.5 cm + 4.5 cm) and vertices, as follows (figure 12): crush the ends of the cut pieces and insert them on both 4.5 cm parts to bind them together; bind the two loose ends of this set by inserting the straight parts of each side of the articulation (taken from 20 straws), forming the vertex which is opposite to the basis of the equilateral triangle (figure 15 and 16).