Converting Degrees and Radians
Multiply by π/180 or 180/π.
Key idea
Multiply by π/180 or 180/π.
In depth
Since 180° = π rad, multiply degrees by π/180 to get radians, and radians by 180/π to get degrees. The conversion factor is just a ratio equal to 1 in different units.
Worked example
60° = 60 × π/180 = π/3. And 3π/4 rad = 3π/4 × 180/π = 135°.
Formula
Real-world uses
- Switching between calculator modes and programming languages that expect radians
Common mistake
Using the factor upside down. Check that the units cancel.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Converting Degrees and Radians?
Multiply by π/180 or 180/π. It is a topic at the intermediate level in Trigonometry.
What is the formula for Converting Degrees and Radians?
The key formula is 180° = π rad.
Where is Converting Degrees and Radians used in real life?
Real-world examples: Switching between calculator modes and programming languages that expect radians.
What should I learn before Converting Degrees and Radians?
Make sure you are comfortable with Radians, the previous topic in Trigonometry.
What is a common mistake with Converting Degrees and Radians?
Using the factor upside down. Check that the units cancel.
How can I practise Converting Degrees and Radians?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Converting Degrees and Radians?
Move on to Right Triangle Terminology next.
Related intermediate topics in Trigonometry
- Radians – Angle measured by arc length on a unit circle; 2π rad = 360°.
- Sine Ratio – Opposite over hypotenuse.
- Cosine Ratio – Adjacent over hypotenuse.
- Tangent Ratio – Opposite over adjacent.
- Reciprocal Trig Functions – Cosecant, secant and cotangent.
- Solving Right Triangles – Find all sides and angles using ratios and the Pythagorean theorem.