public double RadiansPerUnit {get;}

try
{
  // create a Grad unit
  var grad = AngularUnit.CreateAngularUnit(9105);
  string unitName = grad.Name;                        // Grad
  double conversionFactor = grad.ConversionFactor;    // 0.015708
  double radiansPerUnit = grad.RadiansPerUnit;
  int factoryCode = grad.FactoryCode;                 // 9105

  // convert 10 grads to degrees
  double val = grad.ConvertTo(10, AngularUnit.Degrees);

  // convert 10 radians to grads
  val = grad.ConvertFromRadians(10);
}
catch (ArgumentException)
{
  // ArgumentException will be thrown by CreateAngularUnit in
  // the following scenarios:
  // - if the factory code used is a non-angular factory code
  //   (i.e. it corresponds to square meters which is an area unit code)
  // - if the factory code used is invalid
  //   (i.e. it is negative or doesn't correspond to any factory code)
}

// custom unit - 3 radians per unit
var myAngularUnit = AngularUnit.CreateAngularUnit("myCustomAngularUnit", 3);
string Name = myAngularUnit.Name;                   // myCustomAngularUnit
double Factor = myAngularUnit.ConversionFactor;     // 3
int Code = myAngularUnit.FactoryCode;               // 0 because it is a custom angular unit
double radiansUnit = myAngularUnit.RadiansPerUnit;  // 3

// convert 10 degrees to my unit
double converted = AngularUnit.Degrees.ConvertTo(10, myAngularUnit);
// convert it back to degrees
converted = myAngularUnit.ConvertTo(converted, AngularUnit.Degrees);

// convert 1 radian into my angular units
converted = myAngularUnit.ConvertFromRadians(1);

// get the wkt
string wkt = myAngularUnit.Wkt;

// create an angular unit from this wkt
var anotherAngularUnit = AngularUnit.CreateAngularUnit(wkt);
// anotherAngularUnit.ConversionFactor = 3
// anotherAngularUnit.FactoryCode = 0    
// anotherAngularUnit.RadiansPerUnit = 3