 # Sin and Cos of Complementary Angles

Related Topics:
Common Core (Geometry)
Common Core for Mathematics

Examples, solutions, videos and lessons to help High School students learn how to explain and use the relationship between the sine and cosine of complementary angles.

sin θ = cos(90 - θ)

Common Core: HSG-SRT.C.7

The following diagram shows the Complementary Angle Theorem. Scroll down the page for more examples and solutions using the Complementary Angle Theorem. Sine and Cosine Relationships of Complementary angles
Cofunctions
Sine and Cosine of complementary angles are congruent.
Complementary Angle Theorem

Complementary Angles with Trig Ratios
Complementary angles in trigonometry.
Complementary angles in trigonometry Cofunctions of Complementary Angles Cofunction Identities
This video explains the cofunction identities and how to determine cofunctions given a function value. Most cofunction values are verified on a calculator.

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