Dynamic Geometry Modules


The accordion links below lead to three investigations of special triangles and three investigations of special quadrilaterals.  You can observe the properties of these constructions by dragging the vertices around the screen and note which are preserved.

Triangle investigation 1: The Equilateral Triangle

Move points A and B around to investigate the construction.

Triangle Investigation 2: The Isosceles Triangle

Triangle investigation 3: The Right Triangle

Quadrilateral Investigation 1: The Parallelogram

Sketch 1: Parallelograms can be constructed using any of the definitions of their properties:

  • A quadrilateral with two pair of opposite sides congruent
  • A quadrilateral with two pair of opposite sides parallel
  • A quadrilateral with one pair of opposite sides congruent and parallel
  • A quadrilateral with two diagonals that bisect each other
  • A quadrilateral with adjacent angles that are supplementary

Which of these do you think was used to create the parallelogram shown below?

Quadrilateral Investigation 2: The Kite

Sketch 2: How was this kite constructed? Move the points before you click in the box.

Quadrilateral Investigation 3: The Trapezoid

Sketch 3: How was this trapezoid constructed?  Are all kites considered parallelograms?  Why or why not?

If you would like to link to other investigations of special quadrilaterals and aspects of dynamic geometry, click here to access a geogebra book collection.