Complementary and Supplementary Angles

Two or more angles are called complementary angles when together they add up to 90°

In the example above ∠ADB and ∠BDC are complementary since together they add up to 90°.

Of course ∠ADC = 90°

Two or more angles are called supplementary when they add up to 180°

In the example above ∠x and ∠y are supplementary since together they add up to 180°

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  • soooooooo

    How do we know how to add up an angle

  • maria valenzuela

    the way my old teacher showed me was u have the degrees of the angle, so u just subtract a number from that and add an number to it and if it adds up right, now not all the time will it work but for the most it help me.

  • CatreshaP.

    Can you send me an example on how to plug in the angles? Thanks

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