The yellow triangles outline one of eight faces
of the octahedron within every tetrahedron.

Complexity starts within the sphere.
Several pages are linked to this page. To return, the URL is https://81018.com/tot-2/ or use your “Back” button (top left arrow) within this desktop window. The URL is: https://81018.com/tot-2/
Observe the octahedron. Many students find it difficult at first. Do you see where the heavy dark lines converge just below the lighter yellow horizontal line. Do you see that center tetrahedron with the two heavy dark lines (black and a very dark blue)? In your mind’s eye follow all those edges back inside to centerpoint of the larger octahedron and the largest tetrahedron pictured here. Also, visit the image on this page.