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Instructional Video3:54
Curated OER

What is a Circle?

6th - 11th
A circle is a set of all the points that are equal distance from a center point. Learn the definition of some of the terms that are associated with a circle: diameter, radius, chord.
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Instructional Video6:29
Corbett Maths

Circumference

6th - 12th Standards
Circumference and diameter differ by just a factor of pi. A short video shows viewers how to calculate circumference given the diameter. It also gives an example of determining the diameter given the circumference.
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Instructional Video4:01
Curated OER

How Do You Find the Area of a Circle if You Know the Diameter?

6th - 8th
Do you know the formula to find the area of a circle? Do you know the value of pi? Do you know what the relationship is between diameter and radius? Yes? Then you can solve this problem. If your scholars don't know this formula then this...
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Instructional Video
Khan Academy

SAT Prep: Test 3 Section 2 Part 3

9th - 12th
Math speeds along in this video, which takes students through problems 11-15 on the practice SAT. Sal takes care to show students more than one possible way to solve several problems, allowing them to make the choice based on their own...
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Instructional Video3:44
Corbett Maths

Perimeter of a Semi-Circle

6th - 12th Standards
Surround yourself with knowledge about perimeter. An informative video shows viewers how to find the perimeter of a semicircle. It begins with an explanation of calculating the length of the semicircular arc and ends with adding on the...
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Instructional Video2:49
Corbett Maths

Parts of the Circle

6th - 12th Standards
Before you can do anything with circles, you need to know the parts of the circle. Viewers of a short video see how to label relevant information about a circle. The resource covers radius, diameter, circumference, chord, tangent, arc,...
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Instructional Video
Khan Academy

SAT Prep: Test 1 Section 3 Part 4

9th - 12th
Pushing through to problems 11-12 on page 398 of The Official SAT Study Guide, Sal goes into comprehensive detail on each problem. Problem 11 involves geometry, including the function of pi, and problem 12 involves non-constant slopes....
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Instructional Video3:14
Numberphile

Calculating Pi with Real Pies

9th - Higher Ed
Pie is great for finding pi. A short video shows how to use real pies to calculate pi. The method involves laying out pies along the circumference and along the diameter of a circle, and then finding the ratio of the number of pies.
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Instructional Video16:22
Curated OER

Tau vs. PI

11th - Higher Ed
What�s wrong with Pi? In this video, Sal considers the question whether the number Tau (_), is a better number to use in our trigonometric model then the traditional PI (�). First, Sal reviews the definition of Pi, the trigonometric...
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Instructional Video11:12
Numberphile

Tau vs Pi Smackdown

9th - Higher Ed
Who wins the tau vs pi debate? Two mathematicians share their view of whether tau or pi is better in a video from the Numberphile Pi series. Spoiler alert: Pi wins.