The Angle property allows changing the inclination angle of Series Labels. By default, this property is set to 0 (Series Labels is not inclined). The picture below shows the situation when the Angle property is set to 0:

 

 

The value of the property can be negative and positive. If a value of the property is negative then Series Label is inclined anticlockwise. If the value of the property is positive then Label in inclined clockwise. The picture below shows a chart sample, which the Angle property for Series Labels is set to 45: