How do you know which method to use to solve a triangle?

1 Answer
Oct 13, 2016

Here is a view of methods to solve oblique (non-right) triangles.

Explanation:

Solving oblique triangles involves looking at what information you're given and either applying the Law of Sines or the Law of Cosines to solve the triangle.

The law of sines is #sinA/a = sinB/b = sinC/c# in triangle ABC, while the law of cosines states that #a^2 = b^2 + c^2 - 2(bc)cosA#.

When do we use Law of Sines?

http://www.softschools.com/math/calculus/using_the_law_of_sines_to_find_an_unknown_side/

http://www.algebralab.org/studyaids/studyaid.aspx?file=trigonometry_lawsines2.xml Warning: the angle-side-side case risks to be an ambiguous case: 0, 1 or 2 solutions possible

http://www.varsitytutors.com/precalculus-help/solve-a-triangle-using-the-law-of-sines-asa-saa-aas

When do we use Law of Cosines?

http://www.freelearningchannel.com/l/Content/Materials/Mathematics/Geometry/textbooks/CK12_Geometry/html/8/7.html

http://www.varsitytutors.com/precalculus-help/solve-a-triangle-in-which-3-sides-are-given-sss

Hopefully this helps!