Illustrative Mathematics
What is a Trapezoid? (Part 2)
This collaborative activity investigates the meaning of a trapezoid and a parallelogram. It begins by presenting two different definitions of a trapezoid. Learners are to reason abstractly the difference between the two definitions and...
Balanced Assessment
Plenty of Pentagons
Why are only four colors needed to color webs from regular pentagons, not five? An assessment task requires young mathematicians to first construct regular pentagons using a compass and straightedge, then has them consider a shape...
Education Development Center
Finding Parallelogram Vertices
Four is the perfect number—if you're talking about parallelograms. Scholars determine a possible fourth vertex of a parallelogram in the coordinate plane given the coordinates of three vertices. They read a conversation...
Curated OER
Tessellation Trial and Error
In this interactive instructional activity, students review attributes of equilateral polygons. They are introduced to the concept of a tessellation. Using protractors and pre-cut shapes, students arrange a variety of tiles to create...
Curated OER
Tessellations
Students identify and construct figures that tessellate. They investigate which regular polygons tessellate and how to modify them to make other tessellating figures. Students explore how naturally occurring tessellations have been...
Curated OER
Analyzing Body Angles
Students investigate angles of polygons. For this geometry lesson, students identify the relationship between angles and the number of sides in a polygon. They differentiate between sumilarity anf congruence in angles and sides.
Illustrative Mathematics
All vs. Only Some
All shapes have certain defining attributes that set them apart from others. In order to understand this, young mathematicians look at examples and non-examples of triangles, rectangles, and squares, working as a whole class to create...
Curated OER
Rhombi
Learners examine the rhombi or diamond shape and compare it to the square. Students are challenged to create as many flat rhombus shapes as possible and develop a definition for the rhombus shape in 20 minutes while working in teams of...
Curated OER
Properties of Special Parallelograms
Students identify properties of trapezoids. In this geometry lesson, students are put into groups and use computer programs to analyze polygons. They drag and move the shapes around as they make predictions.
Curated OER
Infinite Secrets
Learners duplicate the method that Archimedes used to estimate the value of pi. They complete a data table and find the approximate values of pi for three sets of polygons.
Curated OER
Area and Perimeter Review
Students calculate the area and perimeter of different shapes. For this geometry lesson, students name the different polygons based on their number of sides. They use the correct formula for each shape to calculate the area and perimeter.
Curated OER
Properties of Special Parallelograms
Learners identify properties of parallelograms. In this geometry lesson, students label polygons as parallelogram or not. They define and label the properties of a kite.
Curated OER
Geometry Scavenger Hunt
Students hunt for hidden geometric shapes and compare the properties of various shapes. In this geometry lesson, students play a game of finding squares, circles, rectangles, and ovals that have been hidden around the classroom. Students...
Curated OER
Tricky Traps
Students create identify properties of trapezoids. In this geometry lesson plan, students calculate the area of given trapezoids and review the area formula for parallelograms. They draw a correlation between the area of a trapezoid and...
Curated OER
A Honey of a Hexagon
Students explore how bees make honey and why the hexagon is the best basic pattern for the honeycomb through the use of a video and hands-on activities with honeycombs and geometric shapes.
Curated OER
Area & Perimeter
Learners define area and perimeter. They demonstrate understanding of the concepts concretely, with manipulatives, and describe with words, their strategies and thought processes.
Curated OER
Coordinate Plane
Tenth graders plot points on a coordinate plane. In this geometry lesson, 10th graders identify the different quadrants, plots points on a number line and coordinate plane and solve for the midpoint of line segments.
Curated OER
Naming Shapes
Students study geometric shapes and practice naming them properly. In this geometry lesson, students work in groups to give definitions of the vocabulary to each other in their own words. Students also visit a lower grade and teach...
Key Curriculum Press
Properties of Special Parallelograms
Rhombuses, rectangles and squares are have special properties. In this activity, young geometers investigate and make conjectures about diagonals, angles, and parallel lines of parallelograms.
Curated OER
Symmetry and Tessellations
Sixth graders investigate tessellations and their origins. Students trace triangles to form a tessellation. They measure the angle of equilateral triangles. Students locate the line of symmetry, they create geometric squares,...