Quadrilaterals

Definition: Quadrilateral with both pairs of opposite angles congruent is called parallelogram. Use Geogebra tools to measure side lengths and slope of 4 sides of the parallelogram below. What do you notice about the side lengths and slopes of the lines in a parallelogram.

Use Geogebra tools and based on your observations from the above investigation construct a quadrilateral that ALWAYS remains as a parallelogram. Color matching is not necessary. How can we formally prove that the quadrilateral formed is always a parallelogram?

Definition: A rectangle is a parallelogram with 4 right angles. Use Geogebra tools to measure and display the lengths and slope of 4 sides of the rectangle below. What, if anything, do you notice?

In the applet (with white background) below, use the tools of Geogebra and your observations in the above investigation to construct a quadrilateral that ALWAYS remains a rectangle. Make sure the angles STAY right angles as you move any vertex (or vertices) around. Be sure your construction reflects this same dynamic behavior. Color matching is not necessary.

Construct