Friday, November 13, 2015

More Shapes and Designs

A student used an angle ruler to measure angles of a polygon during a class investigation

Students have been working on a variety of concepts throughout this unit.  Here's a brief summary:

  • How to sort polygons into classes according to the number, size, and relationship of their sides and angles
  • How to find angle measures by estimation, by use of tools like protractors and angle rulers, and by reasoning with variables and equations
  • Discovering formulas for finding the angle sum of polygons
  • The relationships of complementary and supplementary pairs of angles, and in figures where parallel lines are cut by transversals
  • How to apply angle-side measurement conditions needed for drawing triangles and quadrilaterals with specific properties
  • The tiling and rigidity or flexibility properties of polygons that make them useful in buildings, tools, art and craft designs and natural objects

These students are investigating which regular polygons will tile a surface (tessellate). Through conducting the investigation, students discover that regular polygons must have an angle measure that is a factor of 360 to fit around a vertex in order to tessellate.

As students investigated the concept, they traced the shapes and had to provide written explanations to accompany their diagram about why some polygons would tessellate and some would not.
These students are creating a representation to help them determine (and then prove) why some specific characteristics of triangles will produce a unique shape.

These students are analyzing work from a group in the class to determine if the 3 requirements given would create a unique triangle, or if more than one triangle could be created from the 3 requirements.

Students used polystrips to investigate whether whether or not a triangle can be formed by any 3 side lengths.
We took an opportunity during a double block to display our summer math projects.  During the "gallery walk", students looked for strengths in each other's work and compared strategies for solving problems.  And, we got to learn more about each other! Some pics from the gallery walk....