Nicala's Blog

chapter 9 section 3

we are learning the law of sine

the only time you will use law of sine is when you are working with right triangles and you only use the angle you have and its opposite.

The Formula

sin(angle) multiply sin(angle 2)

opp leg opp leg 2

you have to cross multiply to solve

if you can not use law of sine then you should use law of cosine but that should be your last resort

example problem

in the triangle RST angle S= 146 s=16 and t= 4. Determine whether T exists. If so find all possible answers.

you have draw the triangle.

then you have to fill in the problem.

sin146/ 16= sin T/4
you cross multiply and then you have to find the inverse of sin.

T=sin-1 (4sin146)/(16)
T=8.036

then you draw the coordinating plane.

then make your answer negative and 180.
T= 171.963

you have to add 8.036 to146
then add 171.963 to 146

and whether answer doesnt go over 180 can be your answer.
and you can have two answers.