opp/hyp or y/r

adj/hyp or x/r

opp/adj

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hyp/opp

hyp/adj

adj/opp

0, 30, 45, 60, 90. Refer to the hand trick.

-on the Cartesian plane

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the *counterclockwise angle* measured between the *initial arm and the terminal arm* between 0-360 degrees

the *acute angle* between the *terminal arm and the x-axis*

an angle measured clockwise from the positive y axis

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0-90°

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90-180°

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180-270°

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270-360°

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an equation that is true for all values of the variable (for which the expressions on both sides of the equations are defined)

yield the same expression when:

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