Supplementary Angles definition - Math Open Reference (original) (raw)

| About these ADVERTISEMENTS | | Supplementary AnglesFrom Latin: supplementum - "something added to supply a deficiency" Definition: Two angles that add up to 180° Try this Drag an orange dot. The two angles will change so that they always add to 180° In the figure above, the two angles ∠PQR and ∠JKL are supplementary because they always add to 180° Often the two angles are adjacent, in which case they form a linear pair like this: Similar in concept are complementary angles, which add up to 90°. A way to remember Sometimes it's hard to remember which is which between supplementary (adds to 180°) and complementary (adds to 90°). Here are two memory aids: The phrase "it's right to give compliments" A right angle is 90 degrees and, yes, 'compliment' and 'complement' are not the same word, but it's a way to remember which is which. Put a vertical line on the right of the letter 'c' in 'complementary' to make into a '9'. Complementary angles add to 90. Other angle topics General Angle definition Degrees Radians Angle bisector Subtended angle Interior of an angle Included angle Angle Types Acute angle Right angle Obtuse angles Straight angle Reflex angle Full angle Angle relationships Vertical angles Complementary angles Supplementary angles Linear pair Adjacent angles Corresponding angles Alternate interior angles Alternate exterior angles Interior angles of a transversal Exterior angles of a transversal (C) 2011 Copyright Math Open Reference. All rights reserved | | | ------------------------------------------------------------------------------------------------- | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | |