## Convert an angle in Degrees to Radians in C#

I was recently using Google Maps API geo-location lookups to get the longitude and latitude of an address entered by the user. I wanted to find the distance between a two co-ordinates using the Haversine Formula. To do this I needed to convert my lat/lng co-ordinates into radians. This seemed like an excellent opportunity to create a new extension method to add to Storm‘s library of re-usable code.

The maths to convert an angle from degrees to radians is really quite simple:

(pi / 180) * angle

We can take this simple equation and create either a simple function, or a convenient extension method.

### C# Function

public double ConvertToRadians(double angle) { return (Math.PI / 180) * angle; }

### C# Extension Method

/// <summary> /// Convert to Radians. /// </summary> /// <param name="val">The value to convert to radians</param> /// <returns>The value in radians</returns> public static class NumericExtensions { public static double ToRadians(this double val) { return (Math.PI / 180) * val; } }