Mathematics

• Complementary angles
  Complementary angles
  In geometry, complementary angles are angles whose measures sum to 90°. If the two complementary angles are adjacent their non-shared sides form a right angle....
  
  , in geometry
• Complementarity theory
  Complementarity theory
  A complementarity problem is a type of mathematical optimization problem. It is the problem of optimizing a function of two vector variables subject to certain requirements which include: that the inner product of the two variables must equal zero, i.e.  = 0...
  
  , a concept related to optimization (mathematics)

Physical sciences

• Complementarity (molecular biology)
  Complementarity (molecular biology)
  In molecular biology, complementarity is a property of double-stranded nucleic acids such as DNA, as well as DNA:RNA duplexes. Each strand is complementary to the other in that the base pairs between them are non-covalently connected via two or three hydrogen bonds...
  
  , a property of nucleic acid molecules in molecular biology
• Complementarity (physics)
  Complementarity (physics)
  In physics, complementarity is a basic principle of quantum theory proposed by Niels Bohr, closely identified with the Copenhagen interpretation, and refers to effects such as the wave–particle duality...
  
  , a basic principle of quantum theory
• Quark–lepton complementarity, in models from grand unified theory

Social sciences

• Complementarianism, a social theory of the complementarity of sexes
• Interpersonal compatibility
  Interpersonal compatibility
  Interpersonal compatibility is a concept that describes the long-term interaction between two or more individuals in terms of the ease and comfort of communication.-Existing concepts:...
  
  , the idea in social psychology that people seek others with characteristics that are different from and complement their own
• Complementary good, economics term

See also

• Yin and yang
  Yin and yang
  In Asian philosophy, the concept of yin yang , which is often referred to in the West as "yin and yang", is used to describe how polar opposites or seemingly contrary forces are interconnected and interdependent in the natural world, and how they give rise to each other in turn. Opposites thus only...
  
  , philosophical concept
• Complementary color
  Complementary color
  Complementary colors are pairs of colors that are of “opposite” hue in some color model. The exact hue “complementary” to a given hue depends on the model in question, and perceptually uniform, additive, and subtractive color models, for example, have differing complements for any given color.-...
  
  
• Complement (disambiguation)