(9) Marking the vertices of a cuboctahedron on a sphere
Using [Spherical octacu], mark the vertices of a regular octahedron on the ball. (The photo below shows the arc of a great circle drawn.) By taking the midpoints of the 12 great circles connecting the vertices of a regular octahedron and connecting these midpoints with arcs of the great circles, a cuboctahedron on the sphere is drawn. From the beginning, mark only the vertices of the regular octahedron, and then use the scale of the great atom to mark only the midpoints of two adjacent vertices. These points are the vertices of the cuboctahedron on the sphere. If you erase the regular octahedron, only the cuboctahedron remains. The process of obtaining a cuboctahedron from a cube is also the same. Ⓒ msolid