My family consists of four people.

I will hold my birthday party on the fourth day of the month.

There is a bookshelf in the corner of the room.

Anyhow, we have to solve that problem.

Anyway, I want to go home soon.

He made a model of a regular tetrahedron.

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

In this right triangle, since one angle is 30 degrees, its complementary angle is 60 degrees.

The opposite angles of a quadrangle intersect each other.

The wildebeest is a very rare animal.