Meaning of π :
No matter how big or small a circle, or the units used to measure the circle's circumference and diameter, the ratio of the circle's circumference to its diameter is always the same number. The symbol π is the tag/label we use to identify the ratio of the circumference of a circle to its diameter.

The tags "sin", "cos", and "tan" are also symbols (albeit three letter symbols) used identify ratio of the sides of a triangle.

Meaning of "sin", "cos", "tan"
The ratio of two sides of any right triangle with the same interior angles is always the same number independent of the size of the triangle, the triangle's orientation, or the units used to measure the sides of the triangles. See similar right triangles for some specific example.

There are three ways to form a ratio of the three sides of a triangle (six if you count the inverse ratios also). The symbols "sin", "cos", and "tan" are the tags/labels we use to identify which ratio is which.


Angles of Right Triangles:

Hypotenuse: hyp
The side opposite the right angle
Opposite Side: opp
The side opposite the angle of focus.
Adjacent Side: adj
The side connected to the angle of focus.

Trigonometric Relations for either Angle:

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