Trigonometric Identities and Special Triangles Summary

Trigonometric Identities and Special Triangles

Summary

there are some rules and formulae that are useful when problem solving using trigonometry.

an identity is an equation which is true for all values of the variable.

angles such as 30°, 45° and 60° are used frequently and the trigonometric ratios of these angles can be found from special triangles and given in fraction form.

Key Skills
  • be aware of simple identities and use them if appropriate.
  • be able to find the trigonometric ratios for angles of 30°, 45° and 60° from the special triangles.

Vocabulary

identity, trigonometry, sine, cosine, tangent, equilateral triangle, isosceles triangle.