ACT · Trigonometry · Right triangle trigonometry
Question act-q-00510
Hard Multiple choice No calculator
The question
What is the value of sin(60°)?
- √3/2
- ½
- 1
- 0
Show answer & worked solution
Answer: √3/2
Worked solution. Recall the unit circle: sin(60°) = √3/2.
Why each wrong choice is wrong. The classic distractor swaps sine and cosine values for the same angle. Drilling the unit circle eliminates this entirely.
Test-day tactic. Memorize sine and cosine at 0°, 30°, 45°, 60°, and 90°. The values are short and they appear constantly.
About this question type
Items use SOH-CAH-TOA to find a missing side or angle in a right triangle.
You will see a question shaped like this one on roughly every other official ACT form, typically at the back end of the section, where the score gradient is steepest. Treat any miss in this subtopic as a signal to drill the subtopic page before you do another full practice test.