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Rotational Symmetry


By Janet Goodship (T1138) on Tuesday, October 5, 1999 - 07:16 pm:

Sorry if this is an ultra-simple query, but I would like to know the answer! I've just been informed that it is accepted practice always to rotate shapes in an anti-clockwise direction. Is this true, and if so, why?


By Simon Munday (Sjm78) on Wednesday, October 6, 1999 - 03:52 pm:

Dear Janet,

It is convenient for everyone to agree on which direction of rotation is called positive. The convention is that anticlockwise is positive and clockwise is negative. This goes for all angles for which there is some idea of orientation, not just angles of rotation.

Simon Munday