Angle Classification
Perimeter- Area Formulas
- Volume Formulas
- Triangles
- Parallelogram
- Circle
- Central Median
- Pythagorean Theorem Problems
- Sine Cosine Rule
- Trigonometry
- Definition of line slope
- Vectors
- Analytic Geometry
Trigonometry in geometry
If the angle A is the right angle of the triangle ABC. The length of |AB|, |BC| and |CA| are usualy denoted by c, a and b. Take point B as center of a trigonometric circle (circle with radius = 1).
Now sin(B),cos(B) and 1 are propertional with b, c and a.
|
= |
|
= |
|
=> sin(B) = b/a cos(B) = c/a tan(B) = b/c
and because B + C = 90° =>
cos(C) = b/a sin(C) = c/a tan(C) = c/b
