Q:

Need algorithm for angle of WPF line

What is the "correct" algorithm to calculate the angle in degrees from a WPF Line?

A:

You need atan2. This would however give you the angle in radians, converting to degrees must be easy :-) The angle is calculated as atan2(y2 - y1, x2 - x1), where (x1, y1) and (x2, y2) are your line ends.
Note that the constant pi is available, too.

