Enter the primary (interior) angle (degrees) into the Calculator (or enter the reflex angle). The calculator will evaluate the Reflex Angle.
- All Math and Numbers Calculators
- Helix Angle Calculator
- Coterminal Angle Calculator
- Exterior Angle Calculator
Reflex Angle Formula
RA = 360^\circ - PA
Variables:
- RA is the Reflex Angle (degrees)
- PA is the primary (interior) angle (degrees)
To calculate Reflex Angle (for a primary interior angle PA with 0° < PA < 180°), subtract the primary angle from 360°.
How to Calculate Reflex Angle?
The following steps outline how to calculate the Reflex Angle.
- First, determine the primary (interior) angle (degrees).
- Next, gather the formula from above = RA = 360° − PA.
- Finally, calculate the Reflex Angle.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Primary angle (degrees) = 40, so Reflex angle (degrees) = 360 − 40 = 320.
FAQs
What is a Reflex Angle?
A reflex angle is an angle that measures more than 180 degrees and less than 360 degrees. It is the larger angle between two rays that share a common endpoint.
How do you differentiate between a Reflex Angle and an Obtuse Angle?
An obtuse angle measures more than 90 degrees but less than 180 degrees, whereas a reflex angle measures more than 180 degrees but less than 360 degrees.
Can a Reflex Angle be negative?
In standard geometry, a reflex angle is usually defined as a positive angle between 180° and 360°, so it is not negative. In other contexts (like directed angles in trigonometry), angles can be negative, but you would typically convert to a positive coterminal angle (between 0° and 360°) before calling it “reflex.”
Why is it important to calculate Reflex Angles?
Calculating reflex angles is useful in fields like engineering, architecture, navigation, and mathematics, where you may need the larger rotation/turn between two directions.
