Math Is Fun
Math Is Fun: Triangle Identities
View examples of triangle identities, equations that are true for all triangles: Law of Sines, Law of Cosines, and Law of Tangents. Follow links to learn more about the purpose and examples of each identity.
BBC
Bbc: Gcse Bitesize: Sine and Cosine Rules
BBC provides a three part lesson on solving triangles, by using the sine rule and cosine rule.
CK-12 Foundation
Ck 12: Determination of Unknown Triangle Measures Given Area
[Free Registration/Login may be required to access all resource tools.] Looks at triangle problems where you are given the area and must use trigonometry to find unknown sides or angles.
ClassFlow
Class Flow: The Law of Cosines
[Free Registration/Login Required] This flipchart defines and uses the law of cosines to find the missing sides and angles of oblique triangles.