CTET 2 Math and Science Feb 2015 Paper

In mathematics education, the Van Hiele model is a theory that describes how students learn geometry. The best known part of the Van Hiele model are the five levels which the Van Hieles postulated to describe how children learn to reason in geometry.
Level 2 : Informal Deduction
At this level, students can establish theinterrelationship of properties both within figures (e.g., in a quadrilateral, opposite sides being parallel necessitates opposite angles being equal) and among figures (a square is a rectangle because it has all the properties of a rectangle). Thus they can deduce properties of a figure and recognize classes of figures.Class inclusion is understood. Definitions are meaningful. Informal arguments can be followed and given. The student at this level, however, does not comprehend the significance of deduction as a whole or the role of axioms.