<TextBlock Text="I" FontSize="12" VerticalAlignment="Top" HorizontalAlignment="Left" Background="Black"
                                       FontFamily="Technical Italic, Comic Sans MS, Arial" Panel.ZIndex="4">
                                <TextBlock.RenderTransform>
                                    <TransformGroup>
                                        <RotateTransform Angle="{Binding Path=Angle, Converter={StaticResource AngleConverter}}"></RotateTransform>
                                        <TranslateTransform>
                                            <TranslateTransform.X>
                                                <MultiBinding Converter="{StaticResource XLineCoordConverterSign}" ConverterParameter="0">
                                                    <Binding Path="Radius"/>
                                                    <Binding Path="House1"/>
                                                    <Binding Path="House1"/>
                                                </MultiBinding>
                                            </TranslateTransform.X>
                                            <TranslateTransform.Y>
                                                <MultiBinding Converter="{StaticResource YLineCoordConverterSign}" ConverterParameter="0">
                                                    <Binding Path="Radius"/>
                                                    <Binding Path="House1"/>
                                                    <Binding Path="House1"/>
                                                </MultiBinding>
                                            </TranslateTransform.Y>
                                        </TranslateTransform>
                                    </TransformGroup>
                                </TextBlock.RenderTransform>
                            </TextBlock>

    public class XLineCoordConverterSign : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (values.Length == 3)
            {
                double radius = (double)values[0];
                double angle = (double)values[2];
                double house1 = (double)values[1];
                if (house1 > angle)
                    angle += 360;

                var num = Int32.Parse(parameter.ToString());
                var a = (angle + 30 * num) % 360;
                a = angle - house1;

                return radius + radius * Math.Cos(a * (Math.PI / 180.0));
            }

            return DependencyProperty.UnsetValue;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

                                                 <MultiBinding Converter="{StaticResource XLineCoordConverterSign}" ConverterParameter="0">
                                                    <Binding Path="Radius"/>
                                                    <Binding Path="House1"/>
                                                    <Binding Path="House1"/>
                                                    <Binding Path="FontFamily" RelativeSource="{RelativeSource Self}" UpdateSourceTrigger="PropertyChanged"/>
                                                    <Binding Path="FontSize" RelativeSource="{RelativeSource Self}" UpdateSourceTrigger="PropertyChanged"/>
                                                    <Binding Path="Text" RelativeSource="{RelativeSource Self}" UpdateSourceTrigger="PropertyChanged"/>
                                                </MultiBinding>

  <Binding Path="FontFamily" RelativeSource="{RelativeSource AncestorType=TextBlock}"/>