Instructional Video11:05
Curated OER

Circles: Radius, Diameter and Circumference

For Students 4th - 11th
Fascinating discussion regarding the origin of Pi accompanies a detailed explanation of how to find the circumference of a circle. Since this is the first installment in a series on circles, the concept of circumference is separated into...
Instructional Video5:07
TED-Ed

The Complex Geometry of Islamic Design

For Students 7th - 12th Standards
Discover the prevalence of geometric design in Islamic culture with this wonderful informational video. It begins with an overview of the complexity of designs dating back to the eighth century during early Islam, and then...
Instructional Video1:47
Curated OER

What is a Cylinder?

For Teachers 8th - 10th
Follow along as the instructor explains what makes a solid shape a cylinder. Yes, learning the meaning of these terms: cylinder, base, curved side, curved face, congruent bases, solid, three dimensional, area, circumference, parallel,...
Instructional Video2:44
Curated OER

What is a Cone?

For Teachers 6th - 11th
What are the things that make a shape a cone? Here's a list of things that define a cone: base, height, vertex, radius, curved side. Are you familiar with all these terms? The teacher diagrams a cone and identifies all the components in...
Instructional Video5:22
Curated OER

What is an Angle?

For Teachers 6th - 12th
An angle is formed when two rays share a common endpoint. Want to know more about angles? There are a lot of terms in this lesson. You might have to watch it two or even three times to make sure you understand all the terms. I recommend...
Instructional Video4:45
Curated OER

What is an Angle?

For Teachers 3rd - 6th
An angle is formed when two rays share a common endpoint. Want to know more about angles? There are a lot of terms in this lesson. You might have to watch it two or even three times to make sure you understand all the terms. I recommend...
Instructional Video3:35
TED-Ed

Why Are Manhole Covers Round?

For Students 8th - 12th Standards
Discover the peculiar geometric property of the curve of constant width, the Reuleaux triangle, and their intriguing connection to manhole covers with yet another fascinating TED-Ed video. 
Instructional Video4:21
CK-12 Foundation

Area and Perimeter of Rhombuses and Kites: Lesson

For Students 6th - 10th Standards
Flip the triangles up and create a parallelogram. Using the idea of transformations, the video develops the area formula for rhombi and kites. The segment of an extensive geometry playlist uses the formula to find the areas of different...
Instructional Video
CK-12 Foundation

Ck 12: Elem Math: Overview of Rectangles Squares Circles and Triangles

For Students 2nd - 5th Standards
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on various two dimensional shapes including rectangles, squares, circles and triangles.
Instructional Video
CK-12 Foundation

Ck 12: Elem Math: Overview of Rectangles Squares Circles and Triangles

For Students 3rd - 5th Standards
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on the properties of rectangles, squares, circles and triangles.
Instructional Video
Khan Academy

Khan Academy: Equal Parts of Circles and Rectangles

For Students 1st - 2nd Standards
Sal determines if shapes are divided into 2 or 4 equal sections.
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]