Instructional Video6:01
Curated Video

Identifying Line Symmetry in Irregular Polygons

K - 5th
In this video, the teacher explains how to identify line symmetry in irregular polygons. They discuss the three options for line symmetry - horizontal, vertical, and diagonal - and emphasize the importance of having matching parts when...
News Clip3:23
AFP News Agency

CLEAN : Rihanna among stars to hit designers red carpet

9th - Higher Ed
CLEAN : Rihanna among stars to hit designers red carpet
Instructional Video5:59
Curated OER

How Do You Find the Sum of the Interior Angles of a Polygon?

6th - 10th
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,...
Instructional Video
Sophia Learning

Sophia: The Diagonal of Rectangular Objects

9th - 10th
In this lesson, students will learn the Diagonal of Rectangle Objects by using the Pythagorean Theorem. Students can watch a video tutorial to learn about the concept.
Instructional Video
Khan Academy

Khan Academy: Triangles: Area of Diagonal Triangles of Rectangle Are Equal

9th - 10th
This video shows that the area of diagonal generated triangles of a rectangle are equal.
Instructional Video
Sophia Learning

Sophia: Diagonal

9th - 10th
In this video tutorial, the instructor defines and provides examples of diagonals in polygons. Students can check their understanding with an assessment. [3:21]
Instructional Video
Sophia Learning

Sophia: Diagonals in Regular Polygons

6th - 8th
In this video tutorial, the instructor demonstrates how to determine the number of diagonals in a regular polygon by looking at the number of vertices, and the number of diagonals. Use the formula to complete the assessment to check...
Instructional Video
Sophia Learning

Sophia: Diagonals in Regular Polygons

6th - 8th
In this video tutorial, the instructor uses data to derive the formula to solve for number of diagonals in a regular polygon. Assess understanding with a quiz. [5:43]
Instructional Video
Sophia Learning

Sophia: Diagonals of a Rhombus

9th - 10th
Explore how to solve for the diagonal length of a rhombus when given the area. Assess learning with a quiz.
Instructional Video
Sophia Learning

Sophia: Area of a Rhombus

9th - 10th
This video lesson demonstrates two ways for calculating the area of a rhombus. Students can check their understanding with an assessment. [4:55]
Instructional Video
Sophia Learning

Sophia: Area of Quadrilaterals: Taking' It to the Streets

9th - 10th
This lesson provides a video that shows examples of various quadrilaterals in the real world. A notes sheet follows describing the characteristics of each quadrilateral and how to find the area of several figures. [3:37]
Instructional Video
Khan Academy

Khan Academy: Rhombus Diagonals

9th - 10th
Proof that the diagonals of a rhombus are perpendicular bisectors of each other.
Instructional Video
Sophia Learning

Sophia: Double Diagonals of a Parallelogram: Lesson 4

6th - 8th
This lesson cover the concept that that when both diagonals are drawn in on a parallelogram, two pairs of congruent triangles are formed. It is 4 of 5 in the series titled "Double Diagonals of a Parallelogram."
Instructional Video
Sophia Learning

Sophia: Double Diagonals of a Parallelogram: Lesson 1

6th - 8th Standards
This lesson cover the concept that that when both diagonals are drawn in on a parallelogram, two pairs of congruent triangles are formed. It is 1 of 5 in the series titled "Double Diagonals of a Parallelogram."
Instructional Video
Sophia Learning

Sophia: Double Diagonals of a Rectangle: Lesson 3

6th - 8th
Following this lesson, you'll know that when both diagonals are drawn in on a rectangle, two pairs of congruent isosceles triangles are formed. It is 3 of 5 in the series titled "Double Diagonals of a Rectangle."
Instructional Video
Sophia Learning

Sophia: Double Diagonals of a Rectangle: Lesson 4

6th - 8th
Following this lesson, you'll know that when both diagonals are drawn in on a rectangle, two pairs of congruent isosceles triangles are formed. It is 4 of 5 in the series titled "Double Diagonals of a Rectangle."
Instructional Video
Sophia Learning

Sophia: Double Diagonals of a Rectangle: Lesson 1

6th - 8th
Following this lesson, you'll know that when both diagonals are drawn in on a rectangle, two pairs of congruent isosceles triangles are formed. It is 1 of 5 in the series titled "Double Diagonals of a Rectangle."
Instructional Video
Sophia Learning

Sophia: Double Diagonals of a Parallelogram

6th - 8th Standards
This lesson cover the concept that that when both diagonals are drawn in on a parallelogram, two pairs of congruent triangles are formed.
Instructional Video
Sophia Learning

Sophia: Double Diagonals of a Rectangle

6th - 8th
Following this lesson, you'll know that when both diagonals are drawn in on a rectangle, two pairs of congruent isosceles triangles are formed.
Instructional Video
Sophia Learning

Sophia: Regular Polygon Diagonals Practice

9th - 10th
The instructor of this video lesson demonstrates how to find the number of diagonals in a regular polygon using a formula. [3:01]