The angle of friction of this material is 30 degrees.

It's difficult to solve this hexagonal puzzle.

Mr. Rokkaku is my best friend.

When light enters water, the angle of refraction changes.

The calculation of the spherical angle is a part of geometry.

He was playing the guitar at the street corner.

Shizuka is my best friend.

A diagonal matrix is a matrix in which all elements outside the main diagonal are zero.

The diagonal elements of this matrix are all 1.

She worships the Horned God.