Source: Cyberchase: "Borg of the Ring"
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Finding the Circle's Center
(Video)
National K -12 Subject:
Lesson Plans Using this Resource:
In this video segment from Cyberchase, Matt, Digit and Slider must create an exact copy of a large ring in order to activate a powerful force and foil Hacker. To make sure the copy they make is perfect, they have to know what the “radius” of a circle is and figure out a way to carefully measure it.
Download and ShareHere are some Frame, Focus and Follow-up suggestions for using this video in a math lesson.
What is Frame, Focus and Follow-up?
Frame: All shapes have certain features or properties that help us define them. For example, how do we know when a four-sided shape should be called a square and not a trapezoid? What is it about a circle that makes it a circle? Sometimes measuring helps with the process of defining a shape. Can you think of an example?
Focus: As you watch this segment, ask yourself, “What feature or property of a circle helps Matt, Digit and Slider figure out how to create the exact copy of the ring they need? Was measurement involved?"
Follow Up: How did Matt, Digit and Slider create the exact copy of the ring? What is the “radius"? How would you find the radius of a circular object like a pie plate or Frisbee®? What other properties of a circle would be helpful to know if you had to create an exact duplicate without tracing?
MATT: The fake ring has to look just like the original - the same shape, same size, same everything, or it won't work.
DIGIT: Yeah! How you gonna pull that off?
SLIDER: With this. It's the plan the original ring was made from.
MATT: Whoa! Where'd you get that?
SLIDER: My father. We gotta cut out a circle that matches this ring exactly.
MATT: We need to cut out two circles! One for the inside edge of the ring - the other for the outside edge.
DIGIT: But, how do we know how big to make 'em?
SLIDER: We need to adjust the radius.
DIGIT: Uh huh...What am I missing here?
MATT: Don't worry, Didge. The radius is the distance from the center point out to the edge of the circle. To change how big or small a circle is, just change the radius! I'll show you.
SLIDER: Never Mind. I'll...make it! And I've got just the tool to do that!
MATT: Sheech. What's with this guy?
SLIDER: Inner circle radius: 19 Cyber units. Outer circle radius: 23 cyber units. We just have to put the markings on it.
DIGIT: May I?
SLIDER: Sure.
DIGIT: TADA!
MATT: An exact copy! Let's make the switch.
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