A quadrantal angle is one that is in the
and has a measure that is a multiple
of 90° (or π/2 radians). A quadrantal angle will have its
lying along an x or y axis.
In the figure above, drag the point A around and see which angles are quandrantal angles.
Math Open Reference now has a Common Core alignment.
See which resources are available on this site for each element of the Common Core standards.