In ΔABC, m∠BAC = 60°, m∠ABC = 70°, then generally which method do we use to find the angle ∠ACB?
Deductive
Here we apply the already-known general rule (angle sum property of a triangle = 180°) to a specific given case to find ∠ACB = 180 - 60 - 70 = 50°. Applying a known general principle to a specific case is the Deductive method. Answer: (B) Deductive.