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Arctan Calculator Degrees

Reviewed by Calculator Editorial Team

The arctan calculator degrees tool helps you find the angle whose tangent is a given number. This is useful in trigonometry, navigation, and engineering calculations where you need to determine angles from ratios.

What is Arctan?

The arctangent function, also known as the inverse tangent function, is the inverse of the tangent function. While the tangent function takes an angle and returns a ratio, the arctangent function takes a ratio and returns an angle.

In degrees mode, the arctangent function returns angles between -90° and 90°. This makes it particularly useful for calculating angles in right-angled triangles where you know the ratio of the opposite side to the adjacent side.

How to Calculate Arctan

To calculate the arctangent of a number in degrees:

  1. Identify the ratio of the opposite side to the adjacent side in a right-angled triangle.
  2. Use the arctan function to find the angle θ where tan(θ) equals this ratio.
  3. The result will be in degrees between -90° and 90°.

For example, if you have a right-angled triangle with opposite side 3 units and adjacent side 4 units, the angle θ can be found using arctan(3/4).

Arctan Formula

The arctangent formula in degrees is:

θ = arctan(y/x) × (180/π)

Where:

  • θ is the angle in degrees
  • y is the length of the opposite side
  • x is the length of the adjacent side

This formula converts the result from radians (the native output of most programming languages) to degrees by multiplying by 180/π.

Arctan Examples

Here are some example calculations:

Ratio (y/x) Arctan (degrees) Interpretation
1 45.00° In a 45-45-90 triangle, the angle is 45°
0.5 26.57° For a ratio of 0.5, the angle is approximately 26.57°
-1 -45.00° Negative ratios result in negative angles

These examples show how the arctangent function works with different input ratios.

Arctan Applications

The arctangent function has several practical applications:

  • Navigation: Calculating bearing angles from coordinate differences
  • Engineering: Determining angles in structural designs
  • Physics: Analyzing projectile motion and forces
  • Computer graphics: Calculating angles for 3D transformations
  • Everyday life: Measuring angles in construction and home improvement

Understanding how to calculate and interpret arctangent values is valuable in many technical and practical scenarios.

Arctan FAQ

What is the range of the arctangent function in degrees?

The arctangent function in degrees returns values between -90° and 90°, which corresponds to the range of the tangent function's inverse.

How do I convert radians to degrees for arctangent?

Multiply the radian result by 180/π to convert it to degrees. This calculator does this conversion automatically.

What happens if I enter a negative number in the arctan calculator?

The calculator will return a negative angle between -90° and 0°, representing the angle in the negative direction.