Instructional Video
Virtual Nerd

Virtual Nerd: What Are Vertical Angles?

9th - 10th Standards
Vertical angles are always congruent to one another. Take a look at this tutorial to learn about and see how to identify vertical angles. [4:07]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Regular Polygon?

7th - 9th
View this tutorial to learn what special properties a polygon must have to be called a regular polygon. [5:36]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Rectangle?

9th - 10th Standards
Tutorial provides an introduction to rectangles and explains their special properties. [5:56]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Parallelogram?

9th - 10th Standards
Video tutorial takes a look at parallelograms and explores what kinds of quadrilaterals can also be called parallelograms. [7:17]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Square?

9th - 10th Standards
Video tutorial explores squares and explains their special properties. [5:59]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Rhombus?

9th - 10th Standards
This tutorial introduces you to the rhombus and explains its special properties. [5:15]
Instructional Video
Virtual Nerd

Virtual Nerd: What Are Similar Figures?

7th - 9th Standards
Two figures that are the same shape and have the same angle measurements are similar figures. Learn all about them in this tutorial. [7:22]
Instructional Video
Sophia Learning

Sophia: Classifying Quadrilaterals

9th - 10th
Quadrilaterals are explored in this video lesson. The tutorial describes the characteristics of various quadrilaterals. Students can check their understanding with an assessment. [6:17]
Instructional Video
Sophia Learning

Sophia: Congruence Statement

9th - 10th
This video tutorial demonstrates how to use a congruence statement to prove to objects congruent. A short quiz accompanies the lesson. [1:09]
Instructional Video
Sophia Learning

Sophia: Congruent Triangles

9th - 10th
Congruent triangles are explored in this video lesson. [1:54] The tutorial includes detailed examples and a short assessment.
Instructional Video
Sophia Learning

Sophia: Coordinate Geometry of Parallelograms

9th - 10th Standards
This lesson will demonstrate how to use slope, midpoint, and distance formulas to determine from the coordinates of the vertices if a quadrilateral is a parallelogram in a coordinate plane. Students can check their understanding with an...
Instructional Video
Sophia Learning

Sophia: Coordinate Geometry of Rectangles

9th - 10th Standards
Coordinate geometry of rectangles is investigated in this video lesson. The tutorial demonstrates how to use the midpoint, distance, and slope formulas to determine if a quadrilateral is a rectangle on a coordinate plane. [17:26]
Instructional Video
Sophia Learning

Sophia: Scalene, Isosceles, and Equilateral Triangles

9th - 10th
This video lesson [2:10] shows examples for classifying triangles by their side lengths. Students can check their understanding with an assessment.
Instructional Video
Sophia Learning

Sophia: Similar Figures

9th - 10th
Similar figures are investigated in this video lesson. [4:30] It provides detailed examples using proportional relationships. Students can check their understanding with an assessment.
Instructional Video
Sophia Learning

Sophia: Square Practice Problems

9th - 10th
This video lesson demonstrates how to use the characteristics of a square to find angle measures and side lengths. [4:31]
Instructional Video
Sophia Learning

Sophia: Transformations/rotations of Geometric Figures

6th - 8th Standards
This video lesson [3:32] demsonstrates how to rotate geometric figures in the coordinate plane. Students can check their understanding with an assessment.
Instructional Video
Sophia Learning

Sophia: Triangle Congruence Theorem (Hl)

9th - 10th
This video lesson introduces and provides examples of the Hypotenuse-Leg Triangle Congruence Theorem. Students can check their understanding with an assessment.
Instructional Video
Sophia Learning

Sophia: Area of Regular Polygons

9th - 10th Standards
This video lesson demonstrates how to find the area of any regular polygon using the apothem. Students can check their understanding with an assessment.
Instructional Video
Sophia Learning

Sophia: Properties of Equilateral Triangles

9th - 10th
Equilateral triangles are explored in this learning tutorial, which includes several videos [4:18; 4:18; 3:18] and a PowerPoint presentation. The lesson includes an introduction of equilateral triangles and their key characteristics....
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Figure Out if Two Figures Are Similar?

7th - 9th Standards
Follow along with this tutorial to see an example of how to determine if two given figures are similar. [7:49]
Instructional Video
Khan Academy

Khan Academy: Worked Examples

9th - 10th
Students watch a video about similar and congruent triangles.
Instructional Video
Khan Academy

Khan Academy: Triangles: Congruent Triangle Proof Example

9th - 10th Standards
Students learn how to prove that two triangles are congruent using midpoint of line segments.
Instructional Video
Khan Academy

Khan Academy: Triangles: Congruent Triangle Example 2

9th - 10th Standards
Students watch a video tutorial showing that segments have the same length using triangle congruence properties.
Instructional Video
Sophia Learning

Sophia: Equilateral Triangle Interior Angles Practice Problems: Lesson 4

9th - 10th
This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 4 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."