Reference angles, by definition, always have a measure between 0 and .
Therefore, the reference angle is always coterminal with the original angle θ. In the diagram below θ represents the original angle and R represents the Reference Angle In radian measure, the reference angle $$\text{ must be } \frac{\pi}{2} $$.. Basically, any angle on the x-y plane has a reference angle, which is always between 0 and 90 degrees.

The reference angle is always positive. All you have to do is simply input any positive angle into the field and this calculator will find the reference angle for you. Reference angles will always have a value between 0° and 90°. For graphing, the angle's initial side is the positive x-axis; its terminal side is the green line, because angles are drawn going anti-clockwise.The curved green line shows the given angle.

What is a reference angle .
The reference angle is the positive acute angle that can represent an angle of any measure..

The reference angle $$ \text{ must be } 90^{\circ} $$.. Due to the periodic nature of the trigonometric functions, the value of a trigonometric function at a given angle is always the same as its value at that angle's reference angle, except when there is a variation in sign.

Reference Angle: the acute angle between the terminal arm/terminal side and the x-axis. In other words, the reference angle is an angle being sandwiched by the terminal side and the x-axis. It must be less than 90 degree, and always positive. May 2012 edited May 2012 2 replies Our reference angle calculator is a handy tool for recalculating angles into their acute version. In unit circle, are reference angles are always positive, even given negative angle for its original standard positioned angle? A reference angle is the smallest angle that is formed by the x- axis and the terminal side of the angle θ. This article explains what a reference angle is, providing a reference angle definition.