Chapter 7 of 10All chapters
Chapter 7 of 10
Trigonometry
Angles into lengths.
The three ratios
In a right-angled triangle, sine is opposite over hypotenuse, cosine is adjacent over hypotenuse, and tangent is opposite over adjacent.
- Label the sides relative to the angle you are using, not the diagram's orientation.
- Inverse functions turn a ratio back into an angle.
Beyond right angles
The sine and cosine rules handle any triangle. They are what surveying, navigation and physics use when nothing is conveniently square.