Chapter+9

toc =Chapter 9 - Triangle Trigonometry=

Section 9-1 -
__Solving Right Triangles__ SOH-CAH-TOA

SOH: Sine x = Opposite / Hypotenuse CAH: Cosine x = Adjacent / Hypotenuse TOA: Tangent x = Opposite / Adjacent

Cosecant x = Hypotenuse / Opposite Secant x = Hypotenuse / Adjacent Cotangent x = Adjacent / Opposite



Section 9-2 -
__The Area of a Triangle__

The area K of triangle ABC is: K = 1/2 ab Sin C = 1/2 bc Sin A = 1/2 ac Sin B K=1/2(one side)(another side)(Sin of included angle)



Section 9-3 -
__The Law of Sines__

In triangle ABC, Sin A / a=Sin B / b=Sin C / c



Section 9-4 -
__The Law of Cosines__

In triangle ABC, c² = a² + b² - 2ab cos C cos C= (a² + b² - c²) / 2ab



Chapter Summary


(0,1, or 2 triangles are possible) ||
 * __Given:__ || __Use:__ || __To find:__ ||
 * SAS || law of cosines || the 3rd side and one remaining angle ||
 * SSS || law of cosines || any two angles ||
 * ASA or AAS || law of sines || the remaning sides ||
 * SSA || law of sines || an angle opposite a given side and the 3rd side