Theorems and Properties
Pythagorean Theorem In a right triangle
Where
It only holds in right triangles
Area of a triangle using sine
Where
Property of the angles of a triangle
Where
Basic Trigonometric Ratios
For an angle
Sine
Cosine
Tangent
Reciprocal Trigonometric Ratios
Cosecant
Secant
Cotangent
Inverse Functions
Arcsine
where
Arccosine
where
Arctangent
where
Laws of Sines and Cosines
Law of Sines
Where
Law of Cosines
This law can be used to calculate a side of a triangle when the other two sides and the included angle are known.
Notable Angles
| Angle (degrees) | ||
|---|---|---|
Fundamental Trigonometric Identities
Pythagorean Identity
Tangent and Cotangent Identities
Double Angle Identities
Sine of the double angle
Cosine of the double angle
Tangent of the double angle