4.3 -- Right Triangle Trigonometry

The Six Trigonometric Functions

There are three different lengths of a triangle. One is the side opposite theta, the second is the side adjacent theta, and the last is the hypotenuse (opposite of the right angle). The lengths of these sides can be used to determine the Six Trigonometric Functions which include:

Sine- Opposite/Hypotenuse

Cosine- Adjacent/Hypotenuse

Tangent- Opposite/Adjacent

Cosecant- 1/Sine or Hypotenuse/Opposite

Secant- 1/Cosine or Hypotenuse/Adjacent

Cotangent- 1/Tangent or Adjacent/Opposite

Here is an example of a right triangle, where "A" is theta.

Example:

Hyp-5

Opp-3

Adj-4

Given these numbers for the side lengths and the definitions above, we can find out any of these Six Trigonometric Functions like so:

Sin= 3/5

Cos= 4/5

Tan= 3/4

Csc= 5/3

Sec= 5/4

Cot= 4/3