If 
and 
find A and B
tan (A + B) = 
tan (A + B) = tan 60o
A + B = 60O (i)
tan (A – B) = 
tan (A - B) = tan 30O
A - B = 30 (ii)
On adding both equations, we obtain
2 A = 90
⇒ A = 45
From equation (i), we obtain
45 + B = 60
B = 15o
Therefore, ∠A = 45° and ∠B = 15°
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