Instructional Video9:01
Khan Academy

The Angle Game, Angles and Intersecting Lines, Geometry

9th - 10th
A motivating activity is coupled with the use of algebra to explore the process of identifying the value of an angle. It feels like magic when Sal shows the solution to the final problem. Also, it would be worthwhile to consider using...
Instructional Video5:15
Khan Academy

Angles of Parallel Lines 2, Angles and Intersecting Lines, Geometry

9th - 10th
This resource explores parallel lines and requires students to practice calculations and analyze angles. By asking viewers to decide whether two lines are parallel based on the information given, this second part of the parallel lines...
Instructional Video7:53
Curated OER

Angles Formed Between Transversals and Parallel Lines, Geometry

9th - 10th
While exploring the concept of transversals, Sal discusses corresponding angles, congruent angles, and opposite/vertical angles. He provides a thorough summation of these mathematical concepts. It is the first installment in a series...
Instructional Video9:02
Khan Academy

The Angle Game, Angles and Intersecting Lines, Geometry

9th - 10th
A motivating activity is coupled with the use of algebra to explore the process of identifying the value of an angle. It feels like magic when Sal shows the solution to the final problem. Also, it would be worthwhile to consider using...
Instructional Video5:15
Khan Academy

Angles of Parallel Lines 2, Angles and Intersecting Lines, Geometry

9th - 10th
Providing an exploration of parallel lines, this resource requires students to not only practice calculations, but also to analyze angles. By asking viewers to decide whether two lines are parallel based upon the information given, this...
Instructional Video7:53
Khan Academy

Angles Formed Between Transversals and Parallel Lines, Geometry

9th - 10th
While exploring the concept of transversals, Sal discusses corresponding angles, congruent angles, and opposite/vertical angles. He provides a thorough summation of these mathematical concepts. It is the first installment in a series...
Instructional Video8:12
Khan Academy

SAT Prep: Test 7 Section 8 Part 2

9th - 12th
Continuing his SAT review session, Sal explores problems with slopes, linear equations, and congruent angles. He begins problem 10 (geometry) but finishes the problem in the next video.
Instructional Video5:22
Curated OER

What are Perpendicular Lines?

6th - 10th
Perpendicular lines intersect to form right angles - four of them to be exact. Vertical angles, congruent angles, 90 degrees each, these are some of the special properties of perpendicular lines. Watch this video to find out a couple...
Instructional Video2:47
Curated OER

How Do You Find a Value for x that Makes Two Lines Parallel?

9th - 11th
So you have a transversal line intersecting two parallel lines and you are looking for a value that would make two corresponding angles congruent. You have all the information needed to write an equation to find the value. So write that...
Instructional Video3:29
Curated OER

How Do You Find a Value for x that Makes Two Lines Parallel?

6th - 12th
So you have a transversal line intersecting two parallel lines and you are looking for a value that would make two corresponding angles congruent. You have all the information needed to write an equation to find the value. So write that...
Instructional Video4:45
Curated OER

What are Vertical Angles?

6th - 12th
What makes vertical angles so special? Here's a few words that might help you figure out why: intersecting lines, congruent angles, opposite, supplementary angles. Still wondering? Then watch this video for a good explanation of vertical...
Instructional Video4:42
Curated OER

How Do You Find Missing Angles in a Transversal Diagram?

6th - 10th
Parallel lines with a transversal and one given value, find the value of the other seven angles. There are many geometric terms about angles and lines to know the meaning of and understand their relationship to each other. Understanding...
Instructional Video4:08
Curated OER

What are Vertical Angles?

6th - 8th
What makes vertical angles so special? Here's a few words that might help you figure out why: intersecting lines, congruent angles, opposite, supplementary angles. Still wondering? Then watch this video for a good explanation of vertical...
Instructional Video5:15
Curated OER

What is a Rhombus?

5th - 8th
A closed figure with four sides means it's a quadrilateral. Each of the different types of quadrilaterals have special properties. The instructor in this video explains the special properties of a rhombus. Parallel sides and congruent...
Instructional Video5:37
Curated OER

What is a Regular Polygon?

5th - 8th
What makes a polygon a regular polygon? Does this mean there are irregular polygons? For a polygon to be classified as a regular polygon, all the sides must be congruent and all the angles must be congruent. Those are the two rules that...
Instructional Video7:17
Curated OER

What is a Parallelogram?

6th - 8th
A rectangle, a rhombus, a square, a trapezoid - are any of these a parallelogram? What are the criteria that make a shape a parallelogram? It has something to do with parallel sides, congruent sides, and congruent angles. Help your young...
Instructional Video6:22
Curated OER

What is a Transversal?

6th - 11th
There are two parallel lines intersected by one straight line, what's that one line called? A transversal. There are a few more things to know about transversal lines and the angles they create. What are vertical angles? Are they...
Instructional Video4:28
Curated OER

How Do You Find Missing Angles in an Isosceles Triangle?

6th - 8th
Finding the missing values of two angles in an isosceles triangle is not as difficult as it sounds. But how can two out of three angle's measurements be found? Well, there are special properties about an isosceles triangle which make...