Answer the following questions using the applet.[br]1.　Can you make a quadrilateral of four sides being 2 cm, 3 cm, 3 cm and 9 cm? Why or why not?[br]2.　If a quadrilateral has four equal sides, what are its possible shapes?[br]3.　If a quadrilateral has two pairs of equal opposite sides, what are its possible shapes?[br]4.　If a quadrilateral has two pairs of equal adjacent sides, what is its shape?[br]5.　Make the trapezium of the four sides (from top to bottom) being: [br]　　(a) 4 cm, 4 cm, 4 cm, 6 cm;　　(b) 4 cm, 4 cm, 5 cm, 6 cm;[br]　　(c) 4 cm, 3 cm, 5 cm, 7 cm;　　(d) 3 cm, 3 cm, 5 cm, 7 cm.[br]　　What is the characteristic of trapeziums?

Anthony Or, GeoGebra Institute of Hong Kong.