The Tetrahedron’s Geometry
Desk Exercise Two Model

CUT ALONG THE SOLID LINES
FOLD ALONG THE DOTTED LINES
GLUE ONE FLAP ONLY

CUT ALONG THE SOLID LINES
FOLD ALONG THE DOTTED LINES
GLUE TO MAKE 4 SMALL TETRAHEDRA

CUT ALONG THE SOLID LINES
FOLD ALONG THE DOTTED LINES
GLUE TO MAKE AN OCTAHEDRON