The dogfish is a type of shark that lives in the deep sea.

Important information is included in the square brackets of this sentence.

When light hits a mirror, the angle of incidence and the angle of reflection become equal.

The angle of friction of this material is 30 degrees.

It's difficult to solve this hexagonal puzzle.

Mr. Rokkaku is my best friend.

The opposite angles of a quadrangle intersect each other.

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

We need to calculate the azimuth of this building.

Anyway, we need to contact her.