The name "trigonometry" itself comes from Greek: Trigonon (triangle) + metron (measure)
As you can probably guess, trigonometry is all about triangles!
The most common triangle observed in trigonometry is the right angle triangle. The shortest leg length is called the opposite side, the longer leg length is called the adjacent, and the longest side is called the hypotenuse.
There are three main functions in trigonometry, sine, cosine, and tangent. These all basically mean one side of a triangle divided by another side. There's an acronym to figure this out:
-The sine of an angle is the opposite length divided by the hypotenuse length
-The cosine of an angle is the adjacent length divided by the hypotenuse length
-The tangent of an angle is the opposite length divided by the adjacent length
On most calculators, sine, cosine, and tangent are labelled sin, cos, and tan respectively. These functions can be used to figure out the lengths of the different sides of triangles when given 1 or more side lengths and an angle. I'd like for you to look at this link:
https://www.mathsisfun.com/algebra/trigonometry.html
This will help explain trigonometry much easier. Hopefully this is a good start for you. I'm afraid everything I know might be confusing to you, so I highly suggest starting at that link after reading my answer.
