# sohcahtoa

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

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

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

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

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 $\mathrm{sin}\theta $ is opposite over hypotenuse^{}; the second portion, cah, should recall to memory that $\mathrm{cos}\theta $ is adjacent^{} over hypotenuse; and the third portion, toa, should recall to memory that $\mathrm{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^{} |