Exploring properties of rectangles and parallelograms using dynamic software
http://www.nctm.org/standards/content.aspx?id=25040
A lesson plan for grades 3 and 5 Mathematics
Dynamic geometry software provides an environment in which students can explore geometric relationships and make and test conjectures. In this example, properties of rectangles and parallelograms are examined. The emphasis is on identifying what distinguishes a rectangle from a more general parallelogram.
E-Math Investigations are selected e-examples from the electronic version of the Principles and Standards of School Mathematics (PSSM). The e-examples are part of the electronic version of the PSSM document. Given their interactive nature and focused discussion tied to the PSSM document, the e-examples are natural companions to the i-Math investigations.
North Carolina Curriculum Alignment
Mathematics (2004)
Grade 3
- Goal 3: Geometry - The learner will recognize and use basic geometric properties of two- and three-dimensional figures.
- Objective 3.01: Use appropriate vocabulary to compare, describe, and classify two- and three-dimensional figures.
Grade 5
- Goal 3: Geometry - The learner will understand and use properties and relationships of plane figures.
- Objective 3.02: Make and test conjectures about polygons involving:
- Sum of the measures of interior angles.
- Lengths of sides and diagonals.
- Parallelism and perpendicularity of sides and diagonals.
- Objective 3.02: Make and test conjectures about polygons involving:
