Law of Sines

~This formula can only be used in non-right triangles.

~Can only be used when you have a "pair": an angle and and its opposite side

~Formula:

sinA/a=sinB/b=sinC/c

~You cross multiply to solve

~If you get an inverse, you must have two answers.

~Ex.1: Solve

A=40, a=6, B=60

~180-60-40=80

C=80

sin40/6=sin60/b

bsin40=6sin60

b=6sin60/sin40

b=8.084

sin40/6=sin80/c

csin40=6sin80

c=6sin80/sin40

c=9.193

~Ex.2: Solve

B=66, b=10, C=83

~180-66-83=31

A=31

sin66/10=sin83/c

csin66=10sin83

c=10sin83/sin66

c=10.865

sin66/10=sin31/a

asin66=10sin31

a=10sin31/sin66

a=5.638