Getting in Shape: Exploring Two-Dimensional Figures
Through a series of hands-on investigations, students first explore some
properties of angles and triangles, including the Triangle Inequality Theorem.
Next, students analyze properties of regular polygons and develop formulas
for area and sums of interior and exterior angles. They then explore circles
and develop circumference and area formulas.
NCTM Standard: Geometry
- Analyze characteristics and properties of two- and three-dimensional geometric
shapes and develop mathematical arguments about geometric relationships
- Specify locations and describe spatial relationships using coordinate
geometry and other representational systems
- Apply transformations and use symmetry to analyze mathematical situations
- Use visualization, spatial reasoning, and geometric modeling to solve
problems
NCTM Standard: Measurement
- Understand measurable attributes of objects and the units, systems, and
processes of measurement
- Apply appropriate techniques, tools, and formulas to determine measurements
Primary Mathematical Goals
- Use a protractor, ruler, and compass to draw and measure angles, triangles,
and polygons
- Understand relationships among the sides and angles of triangles, quadrilaterals,
and other polygons
- Create tessellations and other geometric designs
- Explore the relationship between the diameter and the circumference of
a circle
- Develop and apply area formulas for regular polygons and circles
