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Tan Function

This page is specific to the Visual Basic for Applications (VBA) Language Reference for Office 2010.

Returns a Double specifying the tangent of an angle.



The required number argument is a Double or any valid numeric expression that expresses an angle in radians.


Tan takes an angle and returns the ratio of two sides of a right triangle. The ratio is the length of the side opposite the angle divided by the length of the side adjacent to the angle.

To convert degrees to radians, multiply degrees by pi/180. To convert radians to degrees, multiply radians by 180/pi.

This example uses the Tan function to return the tangent of an angle.

Dim MyAngle, MyCotangent
MyAngle = 1.3    ' Define angle in radians.
MyCotangent = 1 / Tan(MyAngle)    ' Calculate cotangent.