2)+About+Trigonometry

===//trig·o·nom·e·try///ˌtrigəˈnämitrē/ === Noun: The branch of mathematics dealing with the relations of the sides and angles of triangles and with the relevant functions of any angles.

Basically, as the name suggests, Trigonometry deals with **triangles**, specifically the **relationships** between their **sides** and the **angles** between sides of these triangles.

**THE BASICS**

So, trigonometry. Sounds pretty hard huh? Fret not, for we shall first touch on the foundations of this topic. Firstly, there are three basic trigonometry functions/identities that you ABSOLUTELY need to know if you want to proceed any further from Page 1 in your textbook, as well as the names of the three sides of a triangle. Here are the three basic functions:**sin, cos and tan,** as well as the three sides of a triangle: **hyp, opp and adj.**


 * HYP, OPP AND ADJ**


 * HYP -** The longest side of a triangle
 * OPP -** The side opposite of angle θ
 * ADJ** - The side adjacent to angle θ


 * SIN **

The symbol for sine. The sine of an angle is the ratio of the length of the opposite side to the length of the hypotenuse.

sin θ = opposite/hypotenuse = c/b

 * Given this equation, it is possible to find the angle given either the hypotenuse and the opposite. For example, if the opposite is given to be 2, you can cross multiply the two expressions, after which you will get the equation sin θ x 2 = hypotenuse. Therefore, you can then find out the hypotenuse. Likewise, you can find the opposite by knowing the value of the opposite.**


 * COS **

The symbol for cosine. The cosine of an angle is the ratio of the length of the adjacent side to the length of the hypotenuse.

cos θ = adjacent/hypotenuse = a/c


 * Therefore, as with the sine, if we are given either the adjacent or the hypotenuse, we can easily find out the length of the other line simply by using the cosine function and cross-multiplying. Easy, isn’t it? We are now down to the last function. **


 * TAN **

The symbol for tangent. The tangent of an angle is the ratio of the length of the opposite side to the length of the adjacent side.

tan θ = adjacent/opposite = a/b


 * Yup, the same rule applies like sin and cos. As you can see, it is so much easier to calculate the length of the triangle with these trigonometry functions! Not so difficult, is it? **

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 * IN CONCLUSION **
 * < **sin** || //·sine// || **S**ine = **O**pposite ÷ **H**ypotenuse ||
 * **cos** || //·cosine// || **C**osine = **A**djacent ÷ **H**ypotenuse ||
 * **tan** || //·tangent// || **T**angent = **O**pposite ÷ **A**djacent ||
 * **hyp** || //·hypotenuse// || The longest side of a right triangle, opposite the right angle ||
 * **opp** || //·opposite// || The side opposite of Angle θ ||
 * **adj** || //·adjacent// || The side next to Angle θ ||

**VARIABLES** In Algebra, we often use x and y for our variables (or in other words unknown values). In Trigonometry, you might notice this symbol: This, theta, is the variable that is used in Trigonometry (: