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...
Sophia Learning
Sophia: Practice Measuring Circular Motion
A narrated screencast which demonstrates how to measure circular motion. [4:41]
AAA Math
Aaa Math: Circumference of a Circle
Calculating the circumference or perimeter of a circle has gotten easier with this formula and practice for finding 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.
BBC
Bbc: Bitesize Review Circle Introduction
Do you need to learn about Pi, circumference, or the area of a circle or just have a quick refresher about them? This British web site will take you through the basics and offers a quick on-line test to help you check your understanding.
Sophia Learning
Sophia: Measuring Circular Motion
Watch this descriptive tutorial, and learn how to figure the rotational motion of an object. [5:23]
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.
PBS
Pbs Learning Media: Finding the Circle's Center
In this video segment [3:10] from Cyberchase, the CyberSquad must find the exact center of a circle in order to save Motherboard.
Mathigon
Mathigon: Geometry: Circle and Pi: Degrees and Radians
Rather than dividing a circle into some number of segments (like 360 degrees), mathematicians often prefer to measure angles using the circumference of a unit circle - a circle with radius 1. This way of measuring angles is called...
Khan Academy
Khan Academy: Arc Measure
Use the fact that the arc measures of a circle must sum to 360 degrees to find missing arc measures. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Annenberg Foundation
Annenberg Learner: Geometry: Circles: Inscribed Angles
Study inscribed angles in semicircles and quarter-circles. What conjectures can you make about the measure of an inscribed angle in semi- or quarter-circles?
Khan Academy
Khan Academy: Angles in Circles
Practice measuring angles using a circle protractor, solve problems about angles as part of a circle. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Sophia Learning
Sophia: Components of Circular Motion
A video lesson that introduces the components of circular motion. Understand that any objects that rotates around a point is in circular motion. Video also explores how to measure how far an object has rotated. Video gives equation for...
Khan Academy
Khan Academy: Angles in Circles
Practice measuring angles using a circle protractor, solve problems about angles as part of a circle.
CK-12 Foundation
Ck 12: Algebra Ii: 4.3 the Unit Circle
Activities in this lesson explore how to identify the coordinates where special right triangles intersect with the unit circle in all four quadrants, use both degrees and radians to identify angles, and explore angles of different sizes...
CK-12 Foundation
Ck 12: Interactive Geometry: 1.8 Circles
Understand circles and their measurement applications.
Oswego City School District
Regents Exam Prep Center: Area of Polygons and Circles
How would you find the area of a polygon or circle? Explore this concept with engaging activities at this test prep site. Here you will find detailed problem solving strategies with accompanying visuals, a reference table with formulas,...
Illustrative Mathematics
Illustrative Mathematics: 7.g,rp Measuring the Area of a Circle
In this lesson plan, 7th graders answer word problems to determine the area of a circle.
Oswego City School District
Regents Exam Prep Center: Area of Polygons and Circles
A lesson focusing on the area of polygons and the circumference of circles. Engaging, interactive practice worksheet, lesson plan, and related classroom activity complete this lesson.
Texas Instruments
Texas Instruments: Circular Motion
In UCM, the net force called Fc is equal to mv2/r and is directed toward the center. This is demonstrated by an object that is suspended by a string and is moving in a circular path which makes a conical pendulum. In this experiment, you...
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems: Circles
Practice using your graphing calculator for drawing circles and for finding measurements for circles and parts of the circle. If you get stumped or if you would like to check your work, then select the View Solution button, which is...
Texas Instruments
Texas Instruments: Drawing a Line Tangent to a Circle
Students use the drawing and measurement tools of Cabri Jr. to draw a line tangent to a circle. [Requires Adobe Reader.]
Texas Instruments
Texas Instruments: Looking at Statistics Through Circles
In this activity, students will measure round objects to determine the circumference and diameter, and use the data to explore geometric concepts of the circle with statistics.
CK-12 Foundation
Ck 12: Arcs in Circles
[Free Registration/Login Required] Students use the interactive circle to change the measure of the arcs. Click learn more to watch a video and click challenge me to answer a practice question.