Angle2[point, apex, point]
[math]\;\;\;[/math]e.g. Angle2[B,A,C]
returns ∡BAC in the range -π . . . π
More simply, it returns ∡BAC .
Construction: [url]http://www.geogebratube.org/material/show/id/99837[/url]
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An angle has a magnitude and a direction.
To work with angles, we must be able to specify direction, and our tools must respect minimum rotation.
For example, the distance from A to B does not go by way of supermarket C, but is a straight line, [i]unless another path of motion is specified.[/i] There is no other consistent assumption. Likewise with angles. Minimum rotation is the 1-1 mapping of angular measure to linear measure which makes it possible to distinguish other paths of motion.
