The Sine Rule

 

 

 

 

 

 

 

The Cosine Rule

 

 

 

 

 

 

 

 

 

 

Which rule to use ?

 

If you know

 

 AAA – 3 angles

 

not   enough

 information

 

 

 

 

AAS – 2 angles, 1 side 

 

 

Use Sine Rule

 

 

 

 

 

ASS – 1 angle ( not included) , 2 sides

 

 

 

ambiguous case

 

 

 

 

   Using Sine Rule

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alternatively,

 

using cosine rule

 

 

 

 

 

 

 

SAS –  Included angle, 2 sides 

 

  Use  Cosine Rule

 

 

 

 

 

 

 

SSS – 3 sides 

 

Use  Cosine Rule