Curated OER
Circles: Radius, Diameter and Circumference
Fascinating discussion regarding the origin of Pi accompanies a detailed explanation of how to find the circumference of a circle. Since this is the first installment in a series on circles, the concept of circumference is separated into...
Khan Academy
Area of a Circle, Perimeter, Area, and Volume, Geometry
This production, the second installment in a series of circles, demonstrates the process of finding the area of a circle. It is effective as an introductory tool. However, it needs to explain the reasoning behind the formula because that...
Curated OER
Tau vs. PI
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...
Khan Academy
SAT Prep: Test 1 Section 3 Part 4
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....
Khan Academy
SAT Prep: Test 4 Section 4 Part 4
Sal takes a little more time to explain the next two problems as he nears the end of this practice SAT session. He spends about 5 minutes drawing, solving, and discussing problem 17 (geometric line segments) and the next 5 minutes on...
Khan Academy
SAT Prep: Test 4 Section 2 Part 4
Taking time to thoroughly explain and work through problems 15-16, Sal models careful reading and problem solving. He begins problem 17 but continues it in the next video.
Khan Academy
SAT Prep: Test 5 Section 3 Part 5
Problem 15 on the practice SAT (page 657) prompts students to solve a word problem using a number of given constraints. Additional problems involve finding the radius of a circle (given the radius of a smaller circle) and prime...
Khan Academy
SAT Prep: Test 6 Section 7 Part 2
Helping students realize the common missteps in solving the average SAT problem, Sal creates a lens through which students can clearly see the correct and incorrect approach to each type of problem. He points out what a student might...
Khan Academy
SAT Prep: Test 8 Section 2 Part 1
Test eight from The Official SAT Study Guide includes eighteen problems, the first four of which are featured in this video. Basic algebraic expressions, linear equations, tangent circles, and coordinates on a plane test algebra and...
Khan Academy
SAT Prep: Test 6 Section 7 Part 5
On the home stretch of this practice session, Sal completes problems 18 and 19 on page 738 of The Official SAT Study Guide. He begins problem 20, but chooses to finish it in the next video instead of rushing the answer. As always, Sal's...
Khan Academy
SAT Prep: Test 2 Section 3 Part 5
Sal takes viewers into the home stretch of this practice test session from The Official SAT Study Guide. Problems 17-18 are algebraic equations, while problem 19 focuses on area in a given figure (with the use of pi).
Khan Academy
SAT Prep: Test 7 Section 5 Part 2
Complicated word problems and expressions are no match for Sal, and after watching this series, they will be no match for your students either! Sal deftly handles problems involving algebraic equations, averages, and circumference.
Khan Academy
Test 3 Section 2 Part 5
Both algebra and geometry problems are featured in this SAT practice video. Students who struggle to transition between skills on tests (average mean, then diameters and pi, then positive integers) would benefit from Sal's deft handling...
Khan Academy
SAT Prep: Test 5 Section 7 Part 5
Geometry problems on the SAT are often the most difficult for students to solve, let alone master. Focusing on several geometry-related skills (as well a few algebra problems), Sal makes this lesson a valuable resource for viewers who...
Khan Academy
SAT Prep: Test 3 Section 8 Part 3
Geometry and algebra are equally represented in this video, which covers problems 10-14 on the practice SAT. As always, Sal is the expert of quick, efficient ways to solve problems - especially helpful for students who have a difficulty...
Flipped Math
Circles and Arc Lengths
Discuss all things round and round. Pupils review finding area and the circumference of circles and use them to solve problems. Next, they learn about central angles and their relationships to measures of arcs. Learners then find out how...
PBS
Pi Day | All About the Holidays
Pi day is both delicious and informative! Play a short video on Pi Day to explain the basics behind both the holiday and the infinite number.
PBS
Formulas for Circle Area and Circumference: Simple as Pie
Calculating circumference is as easy as pi times diameter. A short video explains how to measure pie tins using the diameter. It also describes the relationship between diameter and circumference. Using the knowledge, scholars consider...
PBS
Scale City — Scaling up Recipes and Circles in the Real World
What a great big skillet you have. The resource introduces the class to the world's largest stainless steel skillet. The class creates a model of the skillet and a typical 12-inch skillet and compares the relative sizes of their areas....
CK-12 Foundation
Calculating Area of a Circle: Lesson
It really is as easy as pi. The segment of a massive geometry playlist points out that the formula for the area of a circle is a relatively simple one. Using the formula, the presenter shows examples of finding the area of circles.
CK-12 Foundation
Circumference: Lesson
It all depends what is given. The section of a large geometry playlist discusses the two formulas for finding the circumference of a circle. With the aid of the formulas, the presenter demonstrates finding the distance around circles in...
CK-12 Foundation
Measuring Arc Length: Lesson
Slice off a piece of pi! A section of an extensive playlist on geometry develops the formula to find the length of an arc. Using the formula, the presentation works through examples finding the arc length, the radius, and the measure of...
Numberphile
Tau vs Pi Smackdown
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.
Numberphile
Pi and Four Fingers
The Simpsons isn't the most likely television show to teach your scholars about math—but it does! An engaging video in the Numberphile "Pi" series explains some math concepts that arise in the show. It also explains some historical...