Mathematics · Grades 10–12
Degrees and radians
A half turn is 180° or π radians.
The key idea
A half turn is 180° or π radians.
radians = degrees × π/180
Worked examples
45° equals kπ radians. Find k as a fraction or integer.
45 × π/180 = 1/4π
1/4
30° equals kπ radians. Find k as a fraction or integer.
30 × π/180 = 1/6π
1/6
Try it yourself
120° equals kπ radians. Find k as a fraction or integer.
240° equals kπ radians. Find k as a fraction or integer.
Check your understanding
Answers and marking notes
- 2/3
120 × π/180 = 2/3π
- 4/3
240 × π/180 = 4/3π
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · teacher review required. Grade bands are approximate, not official curriculum alignment.