sohcahtoa

Let $\theta$ be an acute angle and fix a right triangle having $\theta$ as one of its angles. The trigonometric functions $\sin \theta$, $\cos \theta$, and $\tan \theta$ can be defined as:

$$\sin \theta =\frac{\text{opposite}}{\text{hypotenuse}}$$

$$\cos \theta =\frac{\text{adjacent}}{\text{hypotenuse}}$$

$$\tan \theta =\frac{\text{opposite}}{\text{adjacent}}$$

A mnemonic device for remembering the three given above is sohcahtoa.

The sohcahtoa can be divided up into three portions of three letters each. The first portion, soh, should recall to memory that $\sin \theta$ is opposite over hypotenuse; the second portion, cah, should recall to memory that $\cos \theta$ is adjacent over hypotenuse; and the third portion, toa, should recall to memory that $\tan \theta$ is opposite over adjacent.

I would like to thank Mrs. Sue Millikin for teaching me trigonometric functions using this mnemonic device.

Title	sohcahtoa
Canonical name	Sohcahtoa
Date of creation	2013-03-22 15:59:23
Last modified on	2013-03-22 15:59:23
Owner	Wkbj79 (1863)
Last modified by	Wkbj79 (1863)
Numerical id	13
Author	Wkbj79 (1863)
Entry type	Definition
Classification	msc 97D40
Classification	msc 51-01
Related topic	Adjacent2
Related topic	Opposite2
Related topic	Hypotenuse
Related topic	Trigonometry