Reflective Inquiry: Why Area is Never Negative?

Reflective Thinking is an important process for an educator to be more professional. Educator can have reflective thinking with doing reflective inquiry. The reflective inquiry has a doctrine, that we not receive immediately something into information, but it’s requires examined and proven to be accepted as information. Information that examine in this inquiry is statement about area is never negative. A deep inquiry to prove that area is never negative lead to a re-reconstruction of the belief system within self, thereby generating new perspective and providing alternative solution to answer why area is never negative? Although it’s not clearly defined that area is never negative, why people accept it as a common sense? What underlies that area is never negative, even teacher itself don’t know the reason? Doesn’t teaching without understanding is consider as irresponsible action to student? Worried with this condition researcher try to figure it out and prove area is never negative with relation between measure, metric, dimension, length, and area in real set. Measure is foundation in this relation, with measure defined non-negative, causes metric and dimension defined with non-negative value. Resulting length as measure in dimension one is non-negative and proved that area is never negative.