Question

Because angle A of triangle ABC is obtuse, you conclude that angle B and angle C must be acute. Is this an example of inductive reasoning or deductive reasoning? A. Inductive B. Deductive

Answer 1

I think it's deductive.

Answer 2

Why?

Answer 3

Because you are using a theorem to come to a conclusion.
Since the measures of the angles of a triangle add up to 180, if one angle is more than 90, that leaves less than 90 for the other two angles, which in turn means each of the other two angles must be less than 90 which makes them acute.
When you start with a theorem, and prove something based on it, it's deductive reasoning.