Science quiz
Sine and cosine of the standard angles
Nine angles around the top half of the unit circle, each with a sine and a cosine. An expression appears and you click its exact value.
- Format
- Sort into groups
- Items
- 18 to sort
- Limit
- 2:00
- Level
- Hard
- Checked
- 2026.10.03
- Items
- 18
- Groups
- 9
- Time limit
- 2:00
- A miss
- 2 tries, then the answer is shown
- Each expression appears in turn. Click its value, or press its number.
- The groups never move, so the number keys are quick.
- Skip (0) sends a prompt to the back of the queue.
- Pause whenever you like (Esc). The board hides while the clock is stopped.
Click the exact value of each sine or cosine. The groups appear when you start.
About this quiz
On the unit circle the cosine of an angle is the x coordinate and the sine is the y coordinate. At multiples of 30° and 45° both come out as exact values built from 1/2, √2/2 and √3/2.
- From 0° to 180° the sine is never negative, but the cosine turns negative past 90°.
- sin 45° and cos 45° are equal: both are √2/2.
- Two tries per expression, then the value is shown.
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