CK-12 Foundation
Equations of Circles: Finding the Equation of a Circle
It's all about location and size. With the aid of the interactive, pupils explore the relationship between the location and size of a circle and its equation. The learners use that relationship to determine the equation of a circle given...
Radford University
Building a Recreation Center
It's all about location, location, location. Small groups work to find the best spot for a rec center to serve three different communities. Learners construct the inscribed and circumscribed circles of a triangle to find the best place....
Curated OER
The Circle's Measure
Listen to the story "Sir Cumference and the Dragon of Pi" and solve the riddle and to save Sir Cumference from the knights. Your students will love mixing an activity with story and will practice their measuring skills while completing...
Curated OER
Circle Graphs
In this circle graphs worksheet, students solve and complete 8 different problems that include word problems referring to two different circle graphs shown. First, they follow the directions for each problem and complete the table that...
Curated OER
Exploring Circles
Students explore circles using a graphing calculator. In this circles lesson plan, students write the equation of a circle with a given center and radius length. Students find the most appropriate model for each combination of data they...
Curated OER
Finding Circumference and Area of a Circle
Young geometers explore the concept of circumference and area of circles. They discuss what information is needed to find circumference and area. The resource employs several instructional methods: Frayer Model for Vocabulary, literature...
Curated OER
Quiz: Area of a Circle
Geometers test their mastery at finding the area of a circle with 10 basic problems. Circle diagrams show line segments, points, and diameter. Distance of radii are given. They use pi as 3.14 to calculate the area. No answer key is...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Curated OER
Inscribing a Hexagon in a Circle
This activity is a follow-on activity to inscribing a square in a circle. The overall problem is more complex. It deals with geometric constructions, properties of triangles, and regular hexagons. The final part of the activity finds the...
Curated OER
Circular Motion
A helpful physics presentation will have you talking in circles! The material covers circular motion, and includes diagrams, formulas, and example problems. When used in addition with directed instruction and a teacher-created form of...
Curated OER
Tangent Lines and the Radius of a Circle
Your Geometry learners will collaboratively prove that the tangent line of a circle is perpendicular to the radius of the circle. A deliberately sparse introduction allows for a variety of approaches to find a solution.
Curated OER
Inscribing a Square in a Circle
Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...
NASA
It All Comes Full Circle
How long does it take spacecraft go around the earth? Using the circular orbits of the space shuttle and the International Space Station, groups determine the distance traveled in one revolution, then calculate the distance traveled...
Illustrative Mathematics
Representing Half of a Circle
Geometric shapes make great visual models for introducing young mathematicians to the concept of fractions. Looking at a series of four circles, students are asked to determine whether or not one half of each circle is shaded. To support...
Illustrative Mathematics
Tangent to a Circle From a Point
Learners see application of construction techniques in a short but sophisticated problem. Combining the properties of inscribed triangles with tangent lines and radii makes a nice bridge between units, a way of using information about...
Curated OER
Circles
In this circles worksheet, 10th graders solve and complete 10 different problems that include various parts of a circle. First, they write the name of the designated coordinates in each. Then, students determine the diameter, chord,...
K12 Reader
Anatomy of a Circle
Make sure your learners are well-versed in circles with a reading passage. Pupils will pick up some important circle-related terms as they read and respond to the five included questions.
EngageNY
Rectangles Inscribed in Circles
Putting a rectangular object into a circular one—didn't the astronauts on Apollo 13 have to do something like this? Learners first construct the center of a circle using perpendiculars. They then discover how to inscribe a rectangle in a...
Mathematics Vision Project
Module 5: Circles A Geometric Perspective
Circles, circles, everywhere! Pupils learn all about circles, central angles, inscribed angles, circle theorems, arc length, area of sectors, and radian measure using a set of 12 lessons. They then discover volume formulas through...
Mathematics Vision Project
Circles and Other Conics
Through a variety of hands-on activities and physical scenarios, this far-reaching unit leads learners through an exceptionally thorough exploration of circles and parabolas as conic sections. Geometric construction techniques are used...
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...
Virginia Department of Education
Angles, Arcs, and Segments in Circles
Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...
Mathematics Assessment Project
Calculating Arcs and Areas of Sectors of Circles
Going around in circles trying to find a resource on sectors of circles? Here is an activity where pupils first complete an assessment task to determine the areas and perimeters of sectors of circles. They then participate in an activity...
Curated OER
Circles: Geometry Review Worksheet
Tenth graders solve and complete 14 different geometry problems. First, they find the area and circumference of a circle with a given radius. Then, they find the area between a circle and an inscribed equilateral triangle given the...