Which direction do you measure an angle?

Answer 1

Unfortunately there is no consistent direction: it depends on the context.

If dealing with bearings (eg navigation) North is 000 degrees and the angle is measured in the clockwise direction starting from the Northward direction.

In the context of coordinate geometry, particularly if working with polar coordinates, angles are measured in the anti-clockwise direction, starting with the x-axis (pointing East) as 0 degrees.

Generally speaking, though, angles may be measured in any direction.