Trigonometry
Hypotenuse
Opposite
Adjacent
Trigonometry might sound difficult but it is actually pretty simple! Trigonometry is a Greek word
that means “ Triangle Measure”, trigono for triangle and metry for measure.
There are three names for each side of the right angled triangle. These are: Hypotenuse, Adjacent,
and Opposite. Hypotenuse is the diagonal-like slope of the right angled triangle, adjacent is the
bottom horizontal line in which one end of the hypotenuse is connected to, and opposite is the
height or vertical line of the triangle where one end of the hypotenuse is connected to.
There are three main functions of trigonometry, but let’s find out what is a function. Function is
the input that is operated in a particular operation to form the output. They are also called SOHCAH-TOA.
1. Sine or Sin Theta Function – The formula for this function is Sin Theta = Opposite divided by
the Hypotenuse or Opposite/Hypotenuse.
Example:
Sin Theta = 3/5 or 3 divided by 5.
Hypotenuse = 5
Answer/Output: 0.6
Opposite = 3
Adjacent = 4
2. Cosine or Cos Theta Function – The formula for this function is Cos Theta = Adjacent divided by the
Hypotenuse or Adjacent/Hypotenuse
Example:
Hypotenuse = 5
Opposite = 3
Adjacent = 4
Cos Theta = 4/5 or 4 divided by 5
Answer/Output: 0.8
3. Tangent or Tan Theta Function – The formula for this function is Tan Theta = Opposite divided by
Adjacent or Opposite/Adjacent.
Example:
Hypotenuse = 5
Opposite = 3
Tan Theta = ¾ or 3 divided by 4
Answer/Output = 0.75
Adjacent = 4
UNIT CIRCLE
AXIS Y (0, 1)
AXIS X (1, 0)