# Cos Function

Calculates the cosine of an angle. The angle is specified in radians. The result lies in the range -1.0 to +1.0.

Using the angle Alpha, the Cos Function calculates the ratio of the length of the side that is adjacent to the angle, divided by the length of the hypotenuse in a right-angled triangle.

Cos(Alpha) = Adjacent/Hypotenuse

## Syntax:

```
Cos (Number)
```

## Return value:

Double

## Parameters:

Number: Numeric expression that specifies an angle in radians for which you want to calculate the cosine.

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

degree=(radian*180)/Pi

radian=(degree*Pi)/180

Pi is here the fixed circle constant with the rounded value 3.1415926...

## Example:

```
' The following example allows for a right-angled triangle the input of
' secant and angle (in degrees) and calculates the length of the hypotenuse:
Sub ExampleCosinus
' rounded Pi = 3.1415926...
Dim d1 As Double, dAngle As Double
d1 = InputBox("Enter the length of the adjacent side: ","Adjacent")
dAngle = InputBox("Enter the angle Alpha (in degrees): ","Alpha")
Print "The length of the hypotenuse is"; (d1 / cos (dAngle * Pi / 180))
End Sub
```