HOW TO SOLVE CONTENT
SIN COS AND
TAN - This document explains how to find Sin, Cos,and Tan
SOHCAHTOA of a right triangle given either all side lengths or angle
and one side length
[Document subtitle]
P Denise Smith Of TutorByDenise
404-939-3806
www.tutorbydenise.com
HOW TO SOLVE SIN COS AND TAN - SOHCAHTOA
Sohcahtoa
Sohca...what? Just an easy way to remember how Sine, Cosine and Tangent work:
Soh... Sine = Opposite / Hypotenuse
...cah... Cosine = Adjacent / Hypotenuse
...toa Tangent = Opposite / Adjacent
Right Triangle
OK, let's see what this is all about.
Firstly, the names Opposite, Adjacent and Hypotenuse come from the right triangle:
"Opposite" is opposite to the angle θ
"Adjacent" is adjacent (next to) to the angle θ
"Hypotenuse" is the long one
Adjacent is always next to the angle
(and opposite is opposite the angle)
Sine, Cosine and Tangent
P DENISE SMITH OF TUTORBYDENISE 404-939-3806 1
HOW TO SOLVE SIN COS AND TAN - SOHCAHTOA
And Sine, Cosine and Tangent are the three main functions in trigonometry.
They are often shortened to sin, cos and tan.
The calculation is simply one side of a right angled triangle divided by another side ... we just
have to know which sides, and that is where "sohcahtoa" helps.
For a triangle with an angle θ , the functions are calculated this way:
Sine Function: soh... sin(θ) = opposite / hypotenuse
Cosine Function: ...cah... cos(θ) = adjacent / hypotenuse
Tangent Function: ...toa tan(θ) = opposite / adjacent
Example: what are the sine, cosine and tangent of 30° ?
The classic 30° triangle has a hypotenuse (the long side) of length 2, an opposite side of length 1
and an adjacent side of √3, like this:
Now we know the lengths, we can calculate the functions:
Sine soh... sin(30°) = 1 / 2 = 0.5
Cosine ...cah... cos(30°) = 1.732 / 2 = 0.866
Tangent ...toa tan(30°) = 1 / 1.732 = 0.577
(get your calculator out and check them!)
P DENISE SMITH OF TUTORBYDENISE 404-939-3806 2
HOW TO SOLVE SIN COS AND TAN - SOHCAHTOA
How to Remember
Well, "sohcahtoa" may be easy for you to remember ... but here’s another way to help it:
Sailors Often Have Curly Auburn Hair Till Old Age.
Or perhaps you prefer one of these:
Some Old Horses Can Always Hear Their Owners Approach.
Some Old Hen Caught Another Hen Taking One Away.
P DENISE SMITH OF TUTORBYDENISE 404-939-3806 3