This solid is called a regular icosahedron, and it is made up of 20 equilateral triangles.

His body is very healthy.

He is working around the clock.

Orthoclase is a type of mineral, mainly found in granite.

There are more than a billion quintillion stars in this galaxy.

A regular polyhedron is a polyhedron where all faces are the same shape.

The cathode of this battery is made of copper.

These two variables are in a proportional relationship.

These two variables vary directly.

Masashi is my best friend.