
 Complementary Angles definition  Math Open Reference 
  Similar in concept are supplementary angles, which add up to 180°. 
  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. 
  angle definition, degrees, angle bisector, adjacent angles, complementary angles, supplementary angles, corresponding angles, alternate interior angles, alternate exterior angles, interior angles of a transversal, exterior angles of a transversal, included angle, linear pair, vertical angles, subtended angle, 
 www.mathopenref.com /anglecomplementary.html (245 words) 
