He is studying the shape of a tetrahemihexahedron.

A positive-semidefinite matrix is one of the important concepts in linear algebra.

This 立方半八面體 is one of the shapes in geometry.

This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.

The great icosihemidodecahedron is a cube with a very complex shape.

This is a model of a great icosahemidodecahedron.