The Definition of trig functions
is illustrated in a rightangled triangle. Geometry and numerical
values are related, and it is emphasized that the trig functions do
not change under rescalings of the triangle's size.
The applet is started from the red button in its own window. Suggestion for the classroom to this applet:  Trigonometry  the rightangled triangle (by Karinna Huber, Word document) Also see the learning units under Trigonometry

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