8.1-Law of the Sines
1
2
3
Law of the Sines & Requirements
Examples
Practice Problems
Law of the Sines
2
Law of the Sines
3

Requirements
 Two
sides and an angle opposite to one of them
 SSA
 Two
angles and any side
 AAS
 If
or ASA
these conditions are not met, the problem cannot be
solved with the Law of the Sines
New Calculator Tools
4

Arcsine
 sin-1

Arc-cosine
 cos-1

Arctangent
 tan-1
New Calculator Tools (Cont.)
5

Reverse the trig function process, where:
opp
sin  
hyp
adj
cos  
hyp
opp
tan  
adj
the arc functions provide for:
 opp 
  
sin 
 hyp 
1
1  adj 
  
cos 
 hyp 
 opp 
  
tan 
 adj 
1
Example
6
Example (Cont.)
7
Another Example
8
Another Example (Cont.)
9
Tips
10



Check your calculator settings
Remember the sum of all angles in a triangle is 180
degrees or pi radians
Not all problems can be solved with the Law of
Sines
Practice Problems
11

Page 577
Problems 1-18