Activities

Trigonometry - sine rule


The sine rule is used in triangles that are not right angled when:

  • two angles and one side are known
  • two sides and a non included angle are known.
  • Demonstration of the sine rule - uses the idea of finding the height of a triangle in two different ways.


    When two sides and a non included angle are known, it may be possible to find two different triangles. This is called the ambiguouscase.


    Notes and problems
     

    Always draw accurate sketches of a problem.