Khan Academy
SAT Prep: Test 2 Section 6 Part 2
Reviewing the last problem from the previous video because he feels that he "rushed it," Sal again explains the concept of ratios as it applies to problem 6 on the practice SAT (page 472 in The Official SAT Study Guide). Additional...
Khan Academy
SAT Prep: Test 1 Section 6 Part 4
Number 11 in the practice section of The Official SAT Study Guide begins with finding the perimeter of a given triangle. Once students solve this multiple-choice question, they can find ways to solve the additional problems on the page,...
Curated OER
Telly Plays The Triangle
Big Bird gives Telly a lesson on living vs. non-living things in this film. Telly is afraid to play a musical instrument, a triangle, he is holding because he thinks he might hurt it. After Big Bird tells Telly the triangle isn't living,...
Khan Academy
SAT Prep: Test 3 Section 2 Part 4
Finding perimeters and slopes is the focus of this video, which details ways to solve problems 15-17 on the practice SAT. Even students who are confident in their ability to pass the SAT would benefit from this additional review.
Curated OER
How Do You Find a Scale Factor in Similar Figures?
Three angles of one triangle are equal to the corresponding angles in another triangle. Use a ratio of corresponding sides to find the scale factor. Actually, there are two scale factor values. The instructor will explain how to get both...
Curated OER
Why Are the Angles of Equilateral Triangles Always Equal to 60¼?
Learn how to identify an equilateral triangle by evaluating its congruent sides. Once you've determined that that sides are congruent you'll be able to use the triangle sum theorem to determine the angles in an equilateral triangle. This...
Curated OER
Common Angle Measures
Using a circle with clock like hands, the tutor explains common angle measurements. She shows that a full circular rotation equals 360 degrees, a quarter rotation equals 90 degrees, a three-quarters rotation equals 270 degrees, and a...
Curated OER
How Do You Find a Scale Factor in Similar Figures?
Three angles of one triangle are equal to the corresponding angles in another triangle. Use a ratio of corresponding sides to find the scale factor. Actually, there are two scale factor values. The instructor will explain how to get both...
Curated OER
How Do You Classify Triangles?
Triangles are classified by their angle measurement as well as by the length of their sides. Here are some names that identify the types of triangles: isosceles, equilateral, scalene, obtuse, and acute. Watch this video to learn about...
Curated OER
What are Equilateral, Isosceles, and Scalene Triangles?
Triangles are classified by their angle measurement as well as by the length of their sides. Here are some names that identify the types of triangles: right, isosceles, equilateral, scalene, obtuse, and acute. Watch this video to learn...
Curated OER
What are Acute, Obtuse, and Right Triangles?
Triangles are classified by their angle measurement as well as by the length of their sides. Here are some names that identify the types of triangles: right, isosceles, equilateral, scalene, obtuse, and acute. Watch this video to learn...
Curated OER
How Do You Find the Sum of the Interior Angles of a Polygon?
Squares, pentagons, triangles, polygons. How is it possible to figure out the sum of the interior angles of any of these multi-faceted shapes? There's got to be a formula. Of course there's a formula. That's what algebra is all about,...
Curated OER
How to Make an Origami Paper Hat
This video shows you and your class how to make an origami hat. Why would you do such a thing? If you think about it origami builds eye hand coordination, is fun, is culturally significant, and this hat, is full of measurable angles....