PowerPoint
315deg
30deg
The parameter w and h are used as radius.
Issue https://tools.oasis-org/issues/browse/OFFICE-3711
To get startpoint and endpoint of the arc, intersect leg of the angle with ellipse.
Angle starts at negative y-axis with 0deg and goes to negative x-axis for 90deg.
Arc goes “counter clockwise”.
PowerPoint 2013 preview