Trigonometry is a branch of mathematics that studies triangles and the relationships between their sides and the angles between these sides.

Sinus? Cosinus? Tangent? These may be the only 3 words you remember from your trigonometry class. I remember a fourth one called

Sinus? Cosinus? Tangent? These may be the only 3 words you remember from your trigonometry class. I remember a fourth one called

**SOH CAH TOA**from my favorite high school math teacher.__Remember:__**S**INUS of an angle is the length of its**O**PPOSITE side over the length of the**H**YPOTENUSE, hence**SOH.****C**OSINUS of an angle is the length of its**A**DJACENT side over the length of the**H**YPOTENUSE, hence**CAH**.**T**ANGENT of an angle is the length of its**O**PPOSITE side over its**A**DJACENT side, hence**TOA**.

**SOH CAH TOA**Trigonometry is an important topic in secondary school mathematics. Without a solid foundation in the subject, one cannot excel in differential and integral calculus which are pre-requisite math courses in many university programs.