4 attributes that are shared by all squares, all parallelograms, and all trapezoids
squares- 4 sides, closed, 4 corners, 4 right angles, straight lines
parallelograms-2 pairs of parallel sides, opposite sides are equal, opposite angles are equal, all right angles, closed
trapezoid-2 sides are same length, 1 side that is long and 1 side that is short, 4 corners, closed


