TABLES RELATING TO PARTS I AND II 213 
Given 
Sought 
A, B, a 
C, b , c 
C = 180° - (4 + fl) 
b = sin 5 
sin yl 
a . ~ 
c = —-- sin G 
sin A 
A, a , b 
B , C, c 
. _ 6 sin A 
sin B = - 
a 
C = 180° - (4 + B) 
a sin C 
sin 4 
A,B,C,a 
Area 
. a 2 sin B sin C 
Area = --—.--- 
2 sin A 
C . a, b 
£ (A + B) = 90° - £ C 
tan £ (4 — B) = -—^ tan ^ (4 + 2?) 
A 
A = i(A + B) + i (A - B) 
B 
B = i (A + B) — i (A — B) 
c 
f . ,s cos £ (.'1 + £) 
cos f (A — B) 
sin i (A + B) 
~ (a b) sm i(A-B) 
Area 
Area = £ a b sin C 
dy t)y C 
,4 
Let s = i (a + b + c) 
Then sin iA = ]/ (* ~ fe ) (l zA 
0 c 
14 i/ S ( S — °) 
cos ^ 4 = V —— -- 
b c 
B, C 
Similar formulas 
Area 
\/$ (s — a) (s — b) (s — c) 
