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 3 Section 8 Part 2
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...
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.
Curated OER
Test 2 Section 2 Part 5
Both algebra and geometry problems are featured in this SAT practice video. Students who have a hard time transitioning between skills on tests (average mean, then diameters and pi, then positive integers) would benefit from Sal's deft...
CK-12 Foundation
Segments from Secants and Tangents: Lesson
Squaring the length equals the product of the outside times the whole. The presentation shows how to find a missing length in a tangent segment or secant segment. As part of a geometry playlist, the video provides the formula relating...
CK-12 Foundation
Angles On and Inside a Circle: Lesson
A video introduces methods to find the measure of angles whose vertex is on and inside a circle. Within examples, the section of a larger playlist on basic geometry incorporates several angle measurement theorems.
Krista King Math
Equation, Center and Radius, and Intercepts of a Circle
Working with standard equations is essential to mathematics. The instructor shows pupils how to apply the equation of a circle to determine the center, radius, and intercepts of a circle. Learners then view three examples that...
Curated OER
What is a Circle?
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.
Curated OER
How Do You Find the Radius of a Circle if You Know the Circumference?
So you know the circumference of a circle but not the radius. This tutorial shows you two different formulas commonly associated with circles, determines which formula to use, then puts the formula to work. You'll have no problem...
Curated OER
What is a Sector and Central Angle?
Slice a large piece of pie or slice a small piece of pie? Whichever way you slice it, this piece of pie would be a fraction of the whole pie. This analogy corresponds with the sector of a circle being a piece of the pie. The size of the...
Curated OER
What is Circumference?
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...
Curated OER
How Do You Find the Circumference of a Circle if You Know the Diameter?
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...
Curated OER
What is the Formula for the Area of a Sector of a Circle?
Are you looking for the formula for the area of a sector of a circle? But what's a sector? A sector is just a fraction of the area of a circle. Follow the instructor as she illustrates and labels the different parts of a circle. She also...
Curated OER
How Do You Find the Area of a Circle if You Know the Radius?
There are basically two things you need to know to find the area of a circle. First, you need to use the correct formula. Second, you have to know the value of the radius. If you know these two things then all you have to do is plug the...
Curated OER
How Do You Find the Area of a Circle if You Know the Diameter?
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...
Curated OER
What is the Formula for the Area of a Circle?
Cut up a circle and make a parallelogram! What? No way! Yes way! Watch the instructor illustrate just how to cut up the circle and get that parallelogram to then get the formula for the area of a circle. It really works! Base,...
Other
Mario's Math Tutoring: Act Math 21 Concepts to Boost Your Score
A video [48 mins, 48 sec] explaining 21 different math concepts to help students prepare for the ACT including; circumference; averages; probability; multiplication counting principle; functions; circles; percentages; factoring; rules of...
