Article explaining what lenses are and how they work. At the end of the article, there are links to several hands-on activities for investigating lenses.

A four-lesson tutorial on the reflection and the ray model of light. These complete tutorials include informational text, interactive activities, animations, and quick, interactive comprehension questions.

This lesson focuses on polygons; a polygon is a closed, flat shape that has only straight sides. Polygons can have any number of sides and angles, but the sides cannot be curved.

Get the definition and properties of a polygon. Then explore such topics as: 1) types of polygon 2) area 3) Perimeter 4) angles associated with polygons and 5) names of polygons.

The invention of the telescope helped change our understanding of the universe. This video segment adapted from NOVA looks at Galileo's contribution to this technology. [1:49]

Introduces the concept of polyhedrons by learning the definition, types, and where they are found. Check-out the solved examples for better understanding and try your hand at solving a few interactive questions at the end of the page.

In Spanish. In this interactive unit learn how to calculate intervals of growth and decay, maximum and minimum value of a function, the intervals of concavity and convexity and the turning points of a function.

A "three star geometry problem" requiring knowledge of how to complete geometric proofs to prove that there are no more than five regular convex polyhedra.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to classify a polygon based on its sides and how to determine whether a polygon is convex or concave.

There is exactly one reflection and no rotation that sends the convex quadrilateral ABCD onto itself. What shape(s) could quadrilateral ABCD be? Explain. Aligns with G-CO.A.3.

[Free Registration/Login Required] This flipchart reviews the characteristics of light and its properties. Students are given examples of reflection, refraction, and lens types. An assessment component is included.

This hypertext physics course tutorial on nonfocusing surfaces relates various design principles to good auditorium design. Illustrated.

This site provides definitions of different types of polygons and figures.

Investigate the behavior of light that is reflected off a spherical mirrored surface.

This lesson explores the characteristics of various types of polygons. It includes two PowerPoint presentations that test students' understanding by grouping polygons in the correct categories.

This site from the University of California deals with different applications and topics pertaining to triangles, particularly triangulation.

Students use this tutorial to investigate the refractive ability of converging and diverging lenses.

An illustrated tutorial which takes students step-by-step through the process of drawing ray diagrams.

[Free Registration/Login Required] Learn about the type, size, location, and orientation of the image that forms when a thin lens is used to view an object using this interactive simulation. A PDF worksheet and a video tutorial are also...

Understand how lens curvature, focal length and f-stop are related.

This article from Khan Academy provides information about mirrors. This information is intended for the Class 12 Physics Course (India).

This is a 10-question quiz about thin lenses.

[Free Registration/Login Required] This flipchart introduces fifth graders to the science of light. Principles such as transparent, translucent, opaque, reflection, and refraction are covered. Concave and convex mirrors and lenses are...

This site gives the general definition of a nonagon with examples of a regular (convex) and irregular concave nonagons. There are links to related terms, challenging problems, more information, and the interactive check point involving...