Texas Education Agency
Texas Gateway: Using Logical Reasoning to Prove Conjectures About Circles
Given conjectures about circles, the student will use deductive reasoning and counterexamples to prove or disprove the conjectures.
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Circles
Twenty-three problems present a variety of practice working with various aspects of circles. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View...
Oswego City School District
Regents Exam Prep Center: Circles, Segments, and Area
A wealth of resources to supplement instruction on parts of the circle. Find lessons describing chords, tangents, secants, and segments, as well as related practice quizzes and classroom activities.
Oswego City School District
Regents Exam Prep Center: Circles and Angles
A wealth of material to supplement classroom instruction on circles, angles in circles, and arcs. Find lessons with formulas, diagrams, and example problems with step-by-step solutions, multiple-choice practice quizzes, and activity...
Paul Dawkins
Paul's Online Notes: Algebra: Circles
Detailed math tutorial features notes and examples that illustrate graphing circles.
Math Open Reference
Math Open Reference: Constructions
Learn about drawing shapes using only a compass and straight edge or ruler with out measuring any lengths or angles.
CK-12 Foundation
Ck 12: Geometry Software for Constructions
[Free Registration/Login Required] Students explore the concept of using geometry software to construct geometric shapes by navigating through the interactive learning module and then answering questions that go along with the module....
Science Buddies
Science Buddies: Thinking in (Semi )Circles: The Area of the Arbelos
The arbelos is the white-shaded region between the three semicircles in the illustration at right. In this project, you'll prove an interesting method for determining the area of the arbelos.
Cuemath
Cuemath: Circles
Explore everything about circles. Learn various parts of a circle like a diameter, radius, circumference, circles chord, tangent circles, major arc, segment, sector, and discover other interesting aspects of it. Try your hand at solving...
Cuemath
Cuemath: Diameter
Understand the concept of diameter by learning the definition and symbols. Check-out the solved examples for better understanding and try your hand at solving a few interactive questions at the end of the page.
Cuemath
Cuemath: What Is Pi?
Learn all about pi. This lesson targets what is pi, the pi symbol, the pi number, and the pi circle in the concept of what is pi. Check-out the interactive simulations to know more about the lesson and try your hand at solving a few...
Cuemath
Cuemath: Arc Length
Learn all about arc length. This lesson targets what is arc length and the different formulas used to calculate it. Check-out the interactive simulations to know more about the lesson and try your hand at solving a few interesting...
Cuemath
Cuemath: Central Angle
Learn all about the basic properties of central angles. This lesson targets what is a central angle, central angle formula, central angle calculator, theorem of central angle, how to find central angles, and how to apply them while...
OER Commons
Oer Commons: Measuring Circles
Seventh graders will measure the circumference and diameter of round things in the classroom and discover the ratio pi. They will see that the ratio of a circle's circumference to its diameter can be used to solve for the circumference...
Math Drills
Math Drills: Measurement Worksheets
Download these free worksheets to sharpen your measurement skills. Sheets focus on temperature, conversion, area and perimeter, volume, and more.
E-learning for Kids
E Learning for Kids: Math: Music: 2 D Shapes
Kyan is an African villager. Can you help him name and define different parts of shapes?
E-learning for Kids
E Learning for Kids: Math: Group of Pyramids: 2 D Shapes
Abeni works at the pyramids. Visit her and find out more about circles and triangles.
Houghton Mifflin Harcourt
Holt, Rinehart and Winston: Homework Help Independent Practice: Circles
Get independent practice working with finding the circumference, area and radius of circles. Each incorrect response gets a text box explanation and another try. Correct responses are confirmed.
Math2
Math2: Circles
This site has many useful formulas and examples relating to circles, including related definitions, circumference of a circle, area of a circle, length of a circular arc, area of a circular sector, equation of a circle in cartesian...
Math2
Math2
This is a site for students and teachers of all grade levels. If you are looking for math tables, general information about math topics, or you would like to ask a question, this is the site to visit.
Shodor Education Foundation
Shodor Interactivate: Conic Flyer
"This applet allows the user to create graphs of conic sections. Using slider bars, one can manipulate the function to change the constant values and view the effects of those changes."
National Council of Teachers of Mathematics
The Math Forum: Elementary Geometry Circles
The Math Forum offers an archive of question and answer sessions on circles and how they relate to geometry.
National Council of Teachers of Mathematics
The Math Forum: Pi Day
Need some ideas for Pi Day on March 14th? You can get some great resources at this location. There are all kinds of links available.
Texas Instruments
Texas Instruments: Constructing Circles
In this activity, students will investigate the construction of circles that pass through a given number of points. They will also investigate the number of points needed to generate a unique circle in a plane.