Instructional Video11:05
Curated OER

Circles: Radius, Diameter and Circumference

4th - 11th
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...
Instructional Video4:02
Khan Academy

Area of a Circle, Perimeter, Area, and Volume, Geometry

7th - 10th
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...
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....
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...
Instructional Video9:24
Khan Academy

SAT Prep: Test 4 Section 4 Part 1

9th - 12th
The next section of the practice SAT from The Official SAT Study Guide (page 594) covers simple linear equations and geometric figures. Students will appreciate Sal's quick problem solving and thought process, which is easy to understand...
Instructional Video8:52
Khan Academy

SAT Prep: Test 3 Section 8 Part 2

9th - 12th
Problems 7-9 involve exponents, inequalities, and geometric figures (diameter and radius), all of which Sal explores eagerly. After misreading one problem, he takes care to correct his mistake, showing students how important it is to...
Instructional Video8:38
Khan Academy

Test 3 Section 2 Part 5

9th - 12th
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...
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.
Instructional Video3:52
Curated OER

What is a Sphere?

4th - 7th
The teacher diagrams and explains the different terms of what comprises a sphere. Follow along and learn about the: radius, diameter, great circle, center, and hemisphere.
Instructional Video4:28
Curated OER

What is a Sphere?

6th - 12th
The teacher diagrams and explains the different terms of what comprises a sphere. Follow along and learn about the: radius, diameter, great circle, center, hemisphere
Instructional Video4:21
Curated OER

What is Circumference?

4th - 8th
There are actually two formulas to find the circumference of a circle. One formula is based on knowing the diameter of the circle, and the other is based on knowing the radius of the circle. The instructor illustrates both formulas. She...
Instructional Video3:29
Curated OER

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

6th - 10th
There are two formulas that can be used to find the circumference of a circle. Choose the appropriate formula depending on the given value in the problem. After selecting the correct formula, solve the problem using 3.14 as an estimation...
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...
Instructional Video1:52
Curated OER

Radius, Chord, Diameter, and Secant

9th - 12th
What do a secant, chord, diameter, and radius all have in common? They are all components or measurements of a circle! This clip quickly defines each of these terms using verbal, written, and diagram examples.
Instructional Video3:42
Curated OER

STEMbite: Circumference Mystery

6th - 10th
Middle school mathematicians might be able to follow as Mr. Vander Heuvel explores the relationship between circumference and diameter. The mystery comes in when he uncovers that for every increased increment of one unit in diameter, the...