Alabama Learning Exchange
Polygons-Changing Area Versus Changing Perimeter
Investigate the area and perimeter of polygons in this geometry lesson. Young geometers use grid paper to draw a quadrilateral and calculate its area and perimeter. They also read The Greedy Triangle to identify the changing shape of...
Alabama Learning Exchange
What You Know About the Bermuda Triangle?
Get lost in the classifications. Using the backdrop of the Bermuda Triangle, pupils classify it by angle and side measures. They also learn information about the triangle and its history.
Curated OER
Exploring Polygons and The Greedy Triangle
Excellent lesson! Anne Linehane's geometry story, The Greedy Triangle, offers an opportunity to practice forming various types of polygons with your learners. Using elastic bands (or Chinese jump ropes), partners form the various shapes...
Curated OER
SuperShapes, Part 1; "Tri"ing Triangles
An outstanding lesson on triangles awaits your math scholars. Learners focus on the triangle, which is the strongest of all polygons. They see the role that triangles play in the design of buildings, and learn about triangle...
Mathed Up!
Angles in Polygons
Show your class that finding angle measures is a regular calculation with a resource that provides 12 problems dealing with the measures of angles in regular polygons. Pupils use formulas for the sum of measures of angles in a polygon to...
Willow Tree
Interior Angles, Exterior Angles, and Diagonals of Polygons
How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate the number of...
Arizona Department of Education
Area and Perimeter of Regular and Irregular Polygons
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 irregular...
Illustrative Mathematics
Polygons
Identify shapes based on their attributes. Second graders are tasked to color triangles, quadrilaterals, pentagons, and hexagons specific colors. The one thing these shapes have in common? They are all polygons.
Noyce Foundation
Lyle's Triangles
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....
Curated OER
2-D polygons
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,...
Illustrative Mathematics
Finding Areas of Polygons, Variation 1
An exercise in finding the area of polygons by decomposing into triangles and composing into rectangles is the focus of this resource. Make several copies of the worksheet for each participant. Ask learners to use colored pencils to...
Curated OER
Naming Polygons
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...
Curated OER
Spotting Polygons
See all sides of the story with a worksheet on geometric shapes! After studying the example at the top, which matches polygons with solid figures, second graders circle shapes that are named in the directions. Next, they match polygons...
Curated OER
The Greedy Triangle-Intro to Geometric Shapes
In this geometry lesson plan, learners read The Greedy Triangle and use geoboards to construct geometric shapes. They identify the number of sides and angles each shape has.
Curated OER
Congruent Polygons: Copying Stretchy Shapes
Third graders investigate congruent polygons through dance. In this congruency lesson, 3rd graders do the "brain dance" as a warm up. They review polygon names by singing "The Polygon Chant," before mirroring congruent shapes with a...
Curated OER
Polygons
This resource provides 5 different worksheets on the topic of polygons and symmetry. These worksheets cover rotational symmetry, lines of symmetry, symmetry of regular polygons, special quadiralaterals, and polygon transformation. The...
Curated OER
Properties of Polygons, Same-Length Sides
Can your third graders spot the differences between these geometric shapes? After studying several sections of triangles, rectangles, and other polygons, learners circle the shape described in each set of instructions. For extra...
Curated OER
Napolean Triangle
Young scholars investigate the Napoleon triangle theory. In this polygon lesson, students differentiate between the boundary points, interior and lattice point of a polygon. They apply concepts of equilateral triangles to solve problems.
Illustrative Mathematics
Sum of Angles in a Polygon
How can learners use algebra to solve a geometry problem? Help learners create an equation that shows the relationship between the number of sides of a polygon and the sum of the interior angles. Students are asked to divide the...
EngageNY
Perimeter and Area of Polygonal Regions in the Cartesian Plane
How many sides does that polygon have? Building directly from lesson number eight in this series, learners now find the area and perimeter of any polygon on the coordinate plane. They decompose the polygons into triangles and use Green's...
Radford University
How Much is in There? A Polygon Investigation
Try to find the triangles in various polygons. An investigation has learners develop a formula for the sum of the measures of the interior angles of a polygon. They use manipulatives to partition each polygon into triangles, then...
Education Development Center
Finding Triangle Vertices
Where in the world (or at least in the coordinate plane) is the third vertex? Given two coordinate points for the vertices of a triangle, individuals find the location of the third vertex. They read an account of fictional...
Illustrative Mathematics
Equal Area Triangles on the Same Base II
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
Curated OER
Know Your Polygons!
Learners identify and categorize different polygons. In this polygons lesson plan, students research and identify properties of polygons, identify different polygon shapes, and categorize different triangles and quadrilaterals.