## Trigonometric Mnemonic

At school we had a saying with which to remember the trigonometric forms:

• $\sin(\vartheta) = O/H$
• $\cos(\vartheta) = A/H$, and
• $\tan(\vartheta) = O/A$

in a right-angled triangle, where

• $\vartheta$ is one of the other angles
• $O$ is the short side opposite the angle
• $A$ is the short side adjacent to the angle, and
• $H$ is the hypotenuse (the long side).

The saying was

Some Old Horses
Can Always Hear
Their Owners Approach.