Instructional Video
Khan Academy

Khan Academy: Area of a Circle

For Students 7th - 8th Standards
Models how to calculate the area of a circle when the diameter is known. [4:02]
Instructional Video
Loyola University Chicago

Math Flix: Congruency

For Students 3rd - 8th Standards
This QuickTime movie provides an opportunity to learn about the basic geometric term congruency. As you watch and listen to the teacher and student interact it helps clarify the thinking behind applying this concept.
Instructional Video
Math TV

Math tv.com: Trigonometry: Right Triangle Trigonometry

For Students 9th - 10th
Students review right triangle trigonometry. The resource consists of a worksheet with practice problems and solutions. In the left hand menu, click Trigonometry, Right Triangle Trigonometry.
Instructional Video
Virtual Nerd

Virtual Nerd: Construct Equilateral Triangle and Square Inscribed in a Circle

For Students 9th - 10th Standards
Two videos on geometric constructions. One explains how to construct an equilateral triangle using a ruler and compass. The second describes how to draw a square using a compass and a straightedge.
Instructional Video
Khan Academy

Khan Academy: Angles, Parallel Lines, & Transversals

For Students 4th - 5th Standards
Looks at parallel lines and intersecting lines (transversals), and the angles they form. [7:08]
Instructional Video
Khan Academy

Khan Academy: Recognizing Shapes

For Students 1st - 2nd Standards
Discusses how to identify basic 2D shapes by their properties. [6:08]
Instructional Video
Khan Academy

Khan Academy: Cousin Fal's Shape Collection

For Students 1st - 2nd Standards
Looks at a collection of 2D shapes and discusses how to identify them based on their properties. [4:19]
Instructional Video
Khan Academy

Khan Academy: Intro to Nets of Polyhedra

For Students 4th - 6th Standards
Learn about the nets that represent 3D solids. [6:48]
Instructional Video
Khan Academy

Khan Academy: Recognizing Shapes

For Students K - 1st Standards
Learn the names of different shapes and how to recognize them. [6:08]
Instructional Video
Khan Academy

Khan Academy: Find Measure of Angles Word Problem

For Students 7th
Presents a problem where pie slices are measured in degrees and you must find the angle of your piece. [4:33]
Instructional Video
Khan Academy

Khan Academy: Find Measure of Vertical Angles

For Students 7th Standards
Demonstrates how to find unknown angles for two intersecting lines when some angle information is given. [3:00]
Instructional Video
Khan Academy

Khan Academy: Equal Parts of Circles and Rectangles

For Students 2nd - 3rd Standards
Looks at circles and rectangles that are divided into sections and discusses how to tell if they are in equal parts of halves or fourths. [3:04]
Instructional Video
Khan Academy

Khan Academy: Triangle Inequality Theorem

For Students 9th - 10th
Explains the Triangle Inequality Theorem, which states that the sum of two sides of a triangle is always more than the length of the third side. [5:52]
Instructional Video
Khan Academy

Khan Academy: Slicing a Rectangular Pyramid

For Students 9th - 10th Standards
Demonstrates what types of shapes one can get in a cross-section when a rectangular pyramid is sliced. [3:29]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Transformation?

For Students 9th - 10th Standards
Transformations allow you to change or move a figure. Learn about all the different kinds of transformations by watching this tutorial. [4:18]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Tessellation?

For Students 9th - 10th
You have probably seen tons of tessellations before without even knowing what they are. Learn about tessellations and see some of their interesting qualities by watching this tutorial. [5:00]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Line of Reflection?

For Students 9th - 10th
The line you reflect a figure over is called the line of reflection. Watch this tutorial and learn about the line of reflection. [3:14]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is an Image?

For Students 9th - 10th
When you're dealing with transformations, the new figure you get is called an image. Take a look at this tutorial and learn about images. [3:39]
Instructional Video
Virtual Nerd

Virtual Nerd: What Does Congruent Mean?

For Students 9th - 10th Standards
Video tutorial explores the term congruent which is often used to describe figures that have the same size and shape. [5:21]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Triangle?

For Students 9th - 10th Standards
This tutorial explains triangles and their different types. [5:58]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Degree?

For Students 9th - 10th
Watch this tutorial to learn what a degree is and how it relates to a circle. [3:08]
Instructional Video
Virtual Nerd

Virtual Nerd: What Are Intersecting Lines?

For Students 9th - 10th
Two lines that cut across one another are called intersecting lines. Learn about them by watching this tutorial. [7:19]
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Classify Triangles?

For Students 9th - 10th Standards
If you know what kind of triangle you're looking at, it's much easier to figure out how to solve for various sides and angles. Use this tutorial to practice classifying triangles. [7:15]
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Find a Missing Angle in a Triangle?

For Students 9th - 10th
It's important to remember that the interior angles of a triangle always add up to 180 degrees. This tutorial shows you how to put this knowledge into an equation and solve to find a missing measurement. [4:22]

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