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Math Help - complementary angles

  1. #1
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    complementary angles

    two angles are called complementary angles if they add up to 90 degrees, right?
    then what about 110 and -20? are they complementary? or complementary angles have to be both positive?
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  2. #2
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    When dealing with complementary angles, it's actually their magnitudes (sizes) that have to add to 90^\circ.
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    Quote Originally Posted by Prove It View Post
    When dealing with complementary angles, it's actually their magnitudes (sizes) that have to add to 90^\circ.
    so does that mean 30 and -60 are complementary?
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  4. #4
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    Yes. If you were to draw both on the unit circle, you would have a 90^{\circ} angle.
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