Arccos Calculator
Compute the inverse cosine ($\arccos$) angle value instantly with our interactive real-time projection Unit Circle.
Enter Value
Angle Output
60.00°
What is the Arccos Calculator?
The Arccos (Inverse Cosine) Calculator is a geometric tool used to determine an unknown angle inside a right-angled triangle when you only know the lengths of the Adjacent side and the Hypotenuse.
How It Works (Formula)
The Cosine function takes an angle and outputs a ratio (Adjacent / Hypotenuse). The Inverse Cosine (Arccos) does the exact opposite: it takes that dimensional ratio (a number between -1 and 1) and calculates the original angle.
$$ \theta = \arccos(x) \iff \cos(\theta) = x $$
The fundamental inverse relationship of Cosine.
How to Use It
Enter the numerical ratio of the adjacent side over the hypotenuse. Click calculate, and the tool will instantly output the precise inverse trigonometric result, displaying the missing angle in both Degrees and Radians.