Angle of two points? Isn't that 180, since it's a straight line between them. But if you want to know an angle of a triangle's one corner, I think the only way is to use trigonometric functions. Or you can always measure the angle using a triangle ruler?
I'm assuming you either want the angle >ABC where A and C are your points and B is the origin, or one of the angles AC makes with either the x or y axis when it crosses them. Either of those will require trig, specifically the use of the inverse tangent function.
provides a passable approximation of arctan(x) from -.305 to .359 (less than 0.1 margin of error), so if you know the slopes of the lines AB and BC are between those values, you can use that series instead of arctan in the formula for >ABC, and if you know the slope of AC is in that range, then you can use the series in the the formulas for the angles formed by AC, the x-axis, and the y-axis. That assumes you know enough trig. to figure out the formula you are approximating though!
Continuing that series will yield a better estimate near x=0, but if your slopes aren't nearly zero, your out of luck.
Finally finding about some of the bots that are flooding the users online - bytespider apparently is a huge offender here - ignores robots.txt and comes in from a ton of different IPs
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.