The sign of the angle indicates the direction of movement around the pivot point In the first and second quadrants, a negative value indicates movement in a clockwise direction; in the third and fourth quadrants, the sign is reversed, with negative values indicating counter-clockwise movement.
Note that the frame of reference for the rotate gesture is defined by the first contact point, and not by the contact point's orientation with respect to the screen. For example, a gesture which begins with the moving finger at the nine o'clock position of the pivot point is indistinguishable from one which begins with the moving finger at the twelve o'clock position (assuming the movement is in the same direction in both cases).
The vertext of the angle is defined by the Angle property.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2