Values at 30, 45 and 60 Degrees — Cheat sheet
CHEAT SHEET · FREE
Choose “Save as PDF” in the print dialog.
On this page
All six, at all three angles
| 30∘ | 45∘ | 60∘ |
|---|
| sin | 21 | 21 | 23 |
| cos | 23 | 21 | 21 |
| tan | 31 | 1 | 3 |
| cot | 3 | 1 | 31 |
| sec | 32 | 2 | 2 |
| csc | 2 | 2 | 32 |
In radians
| Degrees | 30∘ | 45∘ | 60∘ |
|---|
| Radians | 6π | 4π | 3π |
Half a turn is π=180∘.
Rebuild it from two triangles
| Triangle | From | Sides |
|---|
| 30-60-90 | half an equilateral triangle of side 2x | x, x3, 2x |
| 45-45-90 | a square of side x cut along its diagonal | x, x, x2 |
The x cancels in every ratio. That is why the size of the triangle never matters.
Patterns
| Pattern | Why |
|---|
| The 30∘ and 60∘ columns are each other reversed | the two angles add to 90∘ |
| sin45∘=cos45∘ | that triangle is isosceles |
| 31 is also written 33 | some books clear the root from the bottom |
| Learn the radians too | calculus never asks in degrees |