<p>using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.IO;
using System.Xml;
using System.Text.RegularExpressions;

public interface IMathUtilities
{
  double MeanAngle(IEnumerable<double> angleValues);
}

public class Solution : IMathUtilities
{
  public double MeanAngle(IEnumerable<double> angleValues)
  {
    return Math.Atan2(angleValues.Sum(i =&gt; Math.Sin(i)) / angleValues.Count(), 
               angleValues.Sum(i =&gt; Math.Cos(i)) / angleValues.Count());
  }
}

</double></double></p>