A systematic approach to proving which quadrilateral is sitting before you. This is a simple, question and answer flow chart that guides students from a 4 sided shape to one of seven possibilities: Square, Rhombus, Rectangle, Parallelogram, Trapezoid, Isosceles Trapezoid, Kite, and non-specific Quadrilateral.
My Geometry students LOVED using this when learning to prove types of quadrilaterals. It begins by asking about parallel sides, then congruent sides, and then to adjacent side slopes. It's a good way to see the connections and differences between the specific types of quadrilaterals.