The calculation of versine is a part of trigonometry.

Masato is my best friend.

He practices every day to learn the correct Chinese pronunciation of characters.

Masasaku is my best friend.

Masatsugu is my best friend.

Shosuke is my best friend.

Kazumasa is my best friend.

This electronic circuit is designed using positive logic.

Positive charge is a type of electric charge of matter.

It's very interesting to learn about the history of the Shōkei era.