Here are seven quadrilaterals. [br]Can you name them? [br]What properties do you associate with each type? [br]Which quadrilaterals are special cases of which other ones? [br]Explore these shapes (by moving the vertices). [br]Why are some vertices green, others red, and still others are not coloured at all? [br]How might you use this applet in teaching, and to which class/grade?