角度からラジアンを求める方法

'角度からラジアンを求める（第2引数をTrueにするとラジアンから角度を求める）※ArcObjectsを使用した場合
Private Function fncDegreeToRadian(Value As Double, Optional Reverse As Boolean = False) As Double
    Dim pAngleFormat As IAngleFormat
    Set pAngleFormat = New AngleFormat
     
    Dim pNumberFormat As INumberFormat
    Set pNumberFormat = pAngleFormat
     
    With pAngleFormat
        If Reverse = False Then
            .AngleInDegrees = False  'Input values are in degrees
            .DisplayDegrees = True  'Display formatted numbers in degrees
            fncDegreeToRadian = pNumberFormat.StringToValue(Value)
        Else
            .AngleInDegrees = True  'Input values are in degrees
            .DisplayDegrees = False  'Display formatted numbers in degrees
            fncDegreeToRadian = pNumberFormat.StringToValue(Value)
        End If
    End With
     
End Function