Texas Instruments
Drawing a Line Tangent to a Circle
Explore lines tangent to a circle. In this math lesson plan, students manipulate circles and lines on a TI calculator. They draw a circle and analyze perpendicular lines intersecting the circle in only one place. This activity...
Curated OER
Circles 1, 2, 3, 4
Here is a way to help your charges identify circles and spheres. In this shapes geometry and technology lesson plan, students identify and draw circles and explain the related attributes. They recognize circles and spheres while...
Illustrative Mathematics
Two Wheels and a Belt
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...
Voyage Solar System
Round and Round We Go — Exploring Orbits in the Solar System
Math and science come together in this cross-curricular astronomy lesson plan on planetary motion. Starting off with a hands-on activity that engages the class in exploring the geometry of circles and ellipses, this lesson...
EngageNY
Circles, Chords, Diameters, and Their Relationships
A diameter is the longest chord possible, but that's not the only relationship between chords and diameters! Young geometry pupils construct perpendicular bisectors of chords to develop a conjecture about the relationships between chords...
Illustrative Mathematics
Alike or Different Game
How are a circle and triangle alike? How are they different? These are the types of questions children will answer while playing this fun geometry game. Including a variety of conventional and unconventional shapes, this activity allows...
EngageNY
Construct a Square and a Nine-Point Circle
Anyone can draw a square, but can you CONSTRUCT a square? Here is a resource that challenges math scholars to create steps to finish their own construction. They test their ability to read and follow directions to complete a construction...
EngageNY
How Do Dilations Map Lines, Rays, and Circles?
Applying a learned technique to a new type of problem is an important skill in mathematics. The lesson plan asks scholars to apply their understanding to analyze dilations of different figures. They make conjectures and conclusions...
EngageNY
Arcs and Chords
You've investigated relationships between chords, radii, and diameters—now it's time for arcs. Learners investigate relationships between arcs and chords. Learners then prove that congruent chords have congruent arcs, congruent arcs have...
Curated OER
Circumscribing a Circle About a Triangle
Pupils circumscribe a circle about a triangle. They construct a triangle using Cabri Jr and then circumscribe it. They then use knowledge of perpendicular bisectors and circumcenters to locate the center of the circle and then...
Curated OER
Circles to Spheres
Students investigate circles and spheres. In this space shapes lesson plan, students compare and contrast two-dimensional and three-dimensional shapes. Students investigate the relationship between plane and space shapes.
Ohio Department of Education
Describing and Creating Plane Figures - Grade One
Young mathematicians draw, create, and describe different shapes using triangles. They discuss attributes of the original and created shapes. Pupils classify the created shapes and draw and write in mathematics journals to communicate...
EngageNY
Construct a Nine-Point Circle
There are an infinite number of points on a circle; can you find nine of them? After putting together a nine-point circle, pupils use constructions and their knowledge of triangle segments to determine the center of the circle. Learners...
EngageNY
Properties of Tangents
You know about the tangent function, but what are tangent lines to a circle? Learners investigate properties of tangents through constructions. They determine that tangents are perpendicular to the radius at the point of tangency,...
West Contra Costa Unified School District
Arcs and Angles
Noah didn't construct this kind of arc. High school scholars first explore how angles can be formed in circles. They then learn relationships between angles and arcs by conducting an exploratory activity where they position and draw arcs...
Curated OER
Bodies In Motion: Shapes and Gestures
Students use geometric shapes to describe body parts. In this geometry lesson, students use geometry vocabulary as they discuss body parts. They practice drawing bodies using shapes based on a wooden model that is poised to show specific...
Curated OER
Geometry Vases: Ceramics Lesson
Geometric shapes are used in math and in art. Learners discuss the various names, dimensions, and attributes of geometric shapes, then apply that knowledge to design a vase. They use 3-D shapes to make a cubist-style vase out of clay.
Curated OER
Perpendicular Segments in a Circle
High schoolers explore the concept of circles as they construct a circle using a program such as Cabri Jr. Learners construct a chord and a diameter that are perpendicular, then measure the bisected chord and notice that both sides of...
Curated OER
Construction Circles
Pupils investigate the number of points needed to determine a unique circle in a plane. Using Cabri Jr., they apply construction techniques to generate a circle that passes through a given number of points.
Curated OER
Conjectures For Intersecting Circles
Students identify properties of circles. In this geometry lesson, students identify the center of two intersecting circles.They use Cabri software to create circles and move it around to make observation.
Curated OER
Circle, Secants
Students identify the secant segment of a circle. In this geometry lesson plan, students investigate secant lines formed outside the circle. They use Cabri software to create drawings and explore circles and secants.
Curated OER
"Sir Cumference and the First Round Table" by Cindy Neuschwander
Students study geometric terms related to circles and solve the problem posed in the book.
Curated OER
City Streets: A Fold-up of a Street Lined with Buildings
After walking in a nearby neighborhood, have your class create this amazing city street pop-up. They study the facades of the buildings they see, focusing on geometric line, shape, and architecture. They then draw, cut, and create a city...
Curated OER
Making and Describing Shapes
Explore the concept of creating and describing 2D and 3D shapes. Using geometry your scholars will describe the attributes of shapes and their properties. They explore and discover what happens when you combine shapes and...