Polygons

Try five problems on triangles. Levels A and B focus on shapes that can be created from right triangles. Level C touches upon the relationship between the area of a six-pointed star and the area of each triangle of which it is composed....

Upper graders label four triangles and fill in the labels correctly. They draw three original triangles and answer the questions about them.

A hands-on activity uses the Zome modeling system, and helps young geometers either learn or review their knowledge of polygons. Students build as many different 2-dimensional polygons as possible: triangle, square, rectangle, pentagon,...

What polygon is this? Young geometers categorize shapes by circling all the quadrilaterals in a set of figures. Next, they write the names of 10 polygons using a visual guide as reference. Review the guide together before they start if...

What shapes classify as a polygon? The resource provides the definition of a polygon and provides examples of polygons and shapes that are not polygons. The presentation gives an explanation of why each shape falls into the particular...

For your eyes only: classify the names of polygons. After providing the definition of a polygon, the video introduces the two major classifications of polygons, concave and convex. The segment of a larger playlist on geometry continues...

Extend young mathematicians' understanding of area with a geometry lesson on trapezoids. Building on their prior knowledge of rectangles and triangles, students learn how to calculate the area of trapezoids and other...

 In this geometry lesson, learners read The Greedy Triangle and use geoboards to construct geometric shapes. They identify the number of sides and angles each shape has.

What makes a figure a polygon? Does it have three or more sides? Is it a closed figure? If the answer is yes to both of those questions then it's a polygon. But wait! Some of these polygons have special names based on the number of sides...

Fourth graders use triangle paper to design patterns using geometric figures and find the areas of those figures by counting units. Students are assessed by determining which figure has the greatest area and explaining their reasoning.