Exact trigonometric values

What you'll learn

1. 1

   Imagine a square with side length 1. Cut it diagonally — you get two right-angled triangles with angles 45°, 45°, 90°.

2. 2

   What is sin 45°?

3. 3

   Let's find sin 30°, cos 30°, and tan 30° using an equilateral triangle split in half.

4. 4

   Drag the sides of this 30-60-90 triangle to match the correct lengths.

5. 5

   What is cos 60°? (Hint: it's the same as sin 30°)

6. 6

   Now let's find sin 0°, cos 90°, and tan 45° using the unit circle.

7. 7

   Which of these is CORRECT?