The Right Hand Rule
Figure (a) shows a disk is rotating counterclockwise when viewed from above. Figure (b) shows the right-hand rule. The direction of angular velocity ω size and angular momentum L are defined to be the direction in which the thumb of your right hand points when you curl your fingers in the direction of the disk's rotation as shown.
Source
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"OpenStax College, College Physics. November 17, 2012."
http://cnx.org/content/m42184/latest/?collection=col11406/1.7
OpenStax CNX
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