Trigonometry

Trigonometry is a subset of Geometry and it is the study of ideas related to Right Triangles.

The study of right triangles regards their sides, their angles and the relationships we find.

As an example, we know that the three angles of any triangle add up to a hundred and eighty degrees. One angle of a right triangle is 90 degrees the other two angles are forced to sum up to 90 degrees and this makes them complementary angles.

It is tradition to draw the triangle as shown below. The sides of the triangle are named relative to the angle theta.

Trigonometric Functions

sin(\theta) = \dfrac {o}{h}

cos(\theta) = \dfrac {a}{h}

tan(\theta) = \dfrac {o}{a}

We have another trick to show you:

\dfrac{o}{a} = \dfrac{o}{h} \dfrac{h}{a}

Reckon that if \dfrac{a}{h} = cos (\theta)[/] then [latex]\dfrac{h}{a} = \dfrac {1}{cos (\theta)} and putting this all together we get the following:

tan(\theta) = \dfrac{sin(\theta)}{cos(\theta)}