| Function | Abbreviation | Sides | Identities | Parts |
|---|---|---|---|---|
| sine | sin | o/h | sin θ = cos (π/2 - θ) = 1/csc θ |  |
| cosine | cos | a/h | cos θ = sin (π/2 - θ) = 1/sec θ | |
| tangent | tan | o/a | tan θ = sin θ/cos θ = cot (π/2 - θ) = 1/cot θ | |
| cotangent | cot | a/o | cot θ = cos θ/sin θ = tan (π/2 - θ) = 1/tan θ | |
| secant | sec | h/a | sec θ = csc (π/2 - θ) = 1/cos θ | |
| cosecant | csc | h/o | csc θ = sec (π/2 - θ) = 1/sin θ |
| Function | 0 (0°) | π/12 (15°) | π/6 (30°) | π/4 (45°) | π/3 (60°) | 5π/12 (75°) | π/2 (90°) |
|---|---|---|---|---|---|---|---|
| sin | 0 | (√6 - √2)/4 | 1/2 | √2/2 | √3/2 | (√6 + √2)/4 | 1 |
| cos | 1 | (√6 + √2)/4 | √3/2 | √2/2 | 1/2 | (√6 - √2)/4 | 0 |
| tan | 0 | 2 - √3 | √3/3 | 1 | √3 | 2 + √3 | ∞ |
| cot | ∞ | 2 + √3 | √3 | 1 | √3/3 | 2 - √3 | 0 |
| sec | 1 | √6 - √2 | 2√3/3 | √2 | 2 | √6 + √2 | ∞ |
| csc | ∞ | √6 + √2 | 2 | √2 | 2√3/3 | √6 - √2 | 0 |