Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Tan Method

Math.Tan Method

Returns the tangent of the specified angle.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public static double Tan(
	double a


Type: System.Double
An angle, measured in radians.

Return Value

Type: System.Double
The tangent of a. If a is equal to NaN, NegativeInfinity, or PositiveInfinity, this method returns NaN.

The angle, a, must be in radians. Multiply by Math.PI/180 to convert degrees to radians.

The following example demonstrates how to calculate the tangent of an angle and display it to the console.

// This example demonstrates Math.Atan()
//                           Math.Atan2()
//                           Math.Tan()
using System;

class Example
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
      double x = 1.0;
      double y = 2.0;
      double angle;
      double radians;
      double result;

      // Calculate the tangent of 30 degrees.
      angle = 30;
      radians = angle * (Math.PI / 180);
      result = Math.Tan(radians);
      outputBlock.Text += String.Format("The tangent of 30 degrees is {0}.", result) + "\n";

      // Calculate the arctangent of the previous tangent.
      radians = Math.Atan(result);
      angle = radians * (180 / Math.PI);
      outputBlock.Text += String.Format("The previous tangent is equivalent to {0} degrees.", angle) + "\n";

      // Calculate the arctangent of an angle.
      String line1 = "{0}The arctangent of the angle formed by the x-axis and ";
      String line2 = "a vector to point ({0},{1}) is {2}, ";
      String line3 = "which is equivalent to {0} degrees.";

      radians = Math.Atan2(y, x);
      angle = radians * (180 / Math.PI);

      outputBlock.Text += String.Format(line1, "\n") + "\n";
      outputBlock.Text += String.Format(line2, x, y, radians) + "\n";
      outputBlock.Text += String.Format(line3, angle) + "\n";
This example produces the following results:

The tangent of 30 degrees is 0.577350269189626.
The previous tangent is equivalent to 30 degrees.

The arctangent of the angle formed by the x-axis and
a vector to point (1,2) is 1.10714871779409,
which is equivalent to 63.434948822922 degrees.


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Community Additions

© 2015 Microsoft