Enter an angle below:

°
  

How does the Reference Angle Calculator work?
Free Reference Angle Calculator - Calculates the reference angle for a given angle. Also known as the positive acute angle.
This calculator has 1 input.

What 4 formulas are used for the Reference Angle Calculator?

Quadrant 1 = θ
Quadrant 2 = 180 -θ
Quadrant 3 = θ - 180
Quadrant 4 = 360 - θ

For more math formulas, check out our Formula Dossier
What 10 concepts are covered in the Reference Angle Calculator?
angle
the figure formed by two rays, called the sides of the angle, sharing a common endpoint, called the vertex of the angle.
cos
cos(θ) is the ratio of the adjacent side of angle θ to the hypotenuse
cot
The length of the adjacent side divided by the length of the side opposite the angle. Also equals 1/tan(θ)
csc
the length of the hypotenuse divided by the length of the adjacent side. Also equals 1/sin(θ)
gradian
defined as one hundredth of the right angle. This is equal to π/200 or 9/10°
radian
a unit of plane angular measurement that is equal to the angle at the center of a circle subtended by an arc whose length equals the radius or approximately 180°/π ~ 57.3 degrees.
reference angle
the smallest possible angle made by the terminal side of the given angle with the x-axis.
sec
the length of the hypotenuse divided by the length of the adjacent side. Also equals 1/cos(θ)
sin
sin(θ) is the ratio of the opposite side of angle θ to the hypotenuse
tan
the ratio of the opposite side to the adjacent side of a particular angle of the right triangle.
Example calculations for the Reference Angle Calculator



Reference Angle Calculator Video