PBS
Pbs Learning Media: Tricking Hacker
In this video segment from Cyberchase, the CyberSquad must reclaim the Totally Rad Ring by measuring its radius to create a perfect duplicate.
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.
Wolfram Research
Wolfram Math World: Pi
This site from Mathworld.com provides a detailed overview of pi. Content includes a diagram, an analysis of its value, how and when pi crops up in mathematics, historical references to pi, and more.
University of South Florida
Fcat: Bubbles: Teacher Notes
Young scholars collect data to determine what happens to the sizes of bubbles when glycerin is added to dish detergent. They will practice their measuring skills and have fun at the same time.
University of North Carolina
A Dictionary of Units of Measurement
This site contains an extensive list of various units of measurement known internationally and across several disciplines. Unit symbols are also included.
Texas Instruments
Texas Instruments: Approximation of Pi
Students will measure the circumference and diameter of a variety of different circles. They will graph the class' values of (d,c) on the coordinate plane and use linear regression to approximate pi.
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.
Texas Instruments
Texas Instruments: Discovering Pi
Students will measure the circumference and diameter of round objects. They will send in their measurements through TI-Navigator and discover the relationship between the circumference and diameter.
Texas Instruments
Texas Instruments: Radius, Diameter, and Circumference of a Circle
In this activity, students will learn the basic concepts of the circle. They explore the relationship between the diameter and the radius, and between the diameter and circumference of a circle. They also get familiar with the Greek...
Texas Instruments
Texas Instruments: Circle Around
In this activity, students compute the circumference and area of circles. They understand that the ratio of the circumference to the diameter is a value called pi. [Requires Adobe Reader.]
Texas Instruments
Texas Instruments: Predicting Pi
In this activity, students explore the use of linear measurement and calculators to discover the existence of pi, the constant ratio between the circumference and the diameter of a circle.
Texas Instruments
Texas Instruments: Constructing the Diameter of a Circle
Given a circle, students will construct a diameter of the circle. They will use the following theorem: In the same circle, if one chord is a perpendicular bisector of another chord, then the first chord is a diameter.
Texas Instruments
Texas Instruments: Circles All Around
This activity provides students an opportunity to explore the relationship between the diameter of a circle and its circumference. [Requires Adobe Reader.]
Science Education Resource Center at Carleton College
Serc: Activity: Identifying a Solid Using Density
Students will measure the length, diameter, and mass of twelve cylinders made of the same element. The first set of measurements are made with a standard metric ruler and 0.1g balance. The measurements are then repeated using a Vernier...
University of Texas at Austin
Mathematics Teks Toolkit: Exploring C/d= Pie
A collection of circular objects will be used to explore circumference and diameter of circles.
Mr. Martini's Classroom
Mr. Martini's Classroom: Circles Geometry Review
This resource provides two levels of multiple choice questions to review the parts of a circle as well as area and perimeter.
PBS
Pbs Mathline: Bubble Mania [Pdf]
Bubble Mania is a lesson plan that focuses on the concept of measurement as it applies to the diameter, circumference, and area in a bubble. Extension activities and connections, related worksheets, and additional resources are included.
PBS
Pbs: The Pantheon
This site from PBS lists the vital statistics of this ancient wonder as well as an explanation of how it was built. Also has a comparison between modern domed buildings and the Pantheon.
Other
Ic Teachers: Shapes, Circles (Basic)
This basic website will give you lots of information about circles. There are also some questions to test your circle knowledge.
Mangahigh
Mangahigh: Pyramid Panic: Basic Shapes to Advanced Geometry
Guide a mummy safely through the burial chambers of a pyramid as you solve length and area problems in basic to advanced geometry. There are four game zones that deal with circles and triangles, quadrilaterals, the Pythagorean Theorem,...
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the area of a circle given its radius or diameter. Students examine guided notes, review guided practice, watch instructional videos and...
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the area of a circle given the radius or the diameter. Students examine guided notes, review guided practice, watch instructional videos...
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the area of a circle given the radius or the diameter. Students examine guided notes, review guided practice, watch instructional videos...
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] In this lesson students calculate the area of circles and the area of sectors of circles by using given information and formulas. Students examine guided notes,...