C# C# Objects Inheritance Inheritance

How to add a new class to it ? I cannot see the option to crate a new file.

How to add a new class to it ? I cannot see the option to crate a new file.

Polygon.cs
namespace Treehouse.CodeChallenges
{
    class Polygon
    {
        public readonly int NumSides;

        public Polygon(int numSides, int sidelength)
        {
            NumSides = numSides;
        }
    }
}

1 Answer