USER’S GUIDE — 105
Law of Cosines
Law of Sines
Heron’s Theorem
Tan =
A
2
r
s–a
()
Tan =
B
2
r
s–b
()
Tan =
C
2
r
s–c
()
s= (a+b+c)
1
2
A
CaB
c
b
a
=
b
=
c
=2R
sin A sin B sin C
R
A
BaC
b
c
a
2
=b
2
+c
2
– 2bccosA
b
2
=c
2
+a
2
– 2cacosB
c
2
=a
2
+b
2
– 2abcosC
APPENDIX D — LAW OF COSINES / HERON’S
THEOREM FORMULAS
