Reflex Angles – More Than a Half Turn
A reflex angle is any angle that measures more than 180° but less than 360° – bigger than a straight angle, but not quite a full turn. Reflex angles can be tricky to spot at first, because in a diagram you're usually looking at the “short way around” between two arms, when the reflex angle is actually the “long way around” on the other side.
The word “reflex” comes from the Latin reflexus, meaning “bent back” – describing how the angle bends back around past a straight line and keeps going, all the way toward a complete rotation.
Recognising a Reflex Angle
A reflex angle measures strictly between 180° and 360°. At any point, the two arms of an angle actually create two angles that sum to 360° – if the angle you want is more than a straight line, it's the reflex one.
250° is between 180° and 360°, so yes, it is reflex.
Real-Life Application
- Pac-Man's mouth: the classic video-game character's open mouth is often drawn as a reflex angle.
- Gymnastics and dance: some extreme body positions involve reflex-angle joint bends.
- Satellite dish coverage: some sensors or dishes describe reflex-angle fields of view.
Key Takeaways
- A reflex angle is between 180° and 360°.
- It represents the “long way around” between two arms of an angle.
- “Reflex” comes from the Latin word for “bent back.”
Practice: Reflex Angles
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