9-3

This week we finished chapter 9, but we did not really learn anything new. It was more of a review. Chapter 9 was one of the easiest for me because there are only 3 formulas that you needed to remember which are Law of Sine, Law of Cosine, and SOHCAHTOA. Law of sine was pretty simple, but not commonly used. You use it when you have a pair of angles.

The formula for law of sine:
Sin(angle) / opposite pair times sin(angle) / opposite pair

Example one: triangle ABC a= 7 c= 3 A= 52 B= 68
Say you are asked to find b. Your first step would be to draw the triangle.

Sin(52 )/ 7 times sin(68) / b

Now, you have to cross multiply, which gives you bsin(52) = 7sin(68).

Divide sin(52) from both sides.
b= 7sin(68)/sin(52)

All you have left to do is plug it into the calculator exactly how you see it.
Answer: b= 8.2