Included here are illustrations of reflections from a plane mirror, a concave mirror and a convex mirror.

A simple activity to investigate how light reflects off a flat surface, a convex one, and a concave one. With a link to an article on reflection.

This lesson will describe what a lens is and how a lens works.

The dynamics of shape in art and the relationship of shape with the other elements of art. The effects of angles and lines on perception.

This site provides a very brief definition to geometric optics, and includes links to related information.

[Free Registration/Login may be required to access all resource tools.] This study guide focuses on polygons: convex vs concave, interior and exterior angles, and basic terminology for common polygons.

Lenses are precisely shaped pieces of glass that have been developed and used in corrective glasses, telescopes, microscopes, binoculars, and magnifying glasses. They can be convex or concave. Links are provided to a video an a test.

This site provides a definition for plane figure (at the top of the page) and a few examples.

This site gives the general definition of a octagon with examples of regular convex and irregular concave octagons. The site has links to related terms, everyday examples, challenging problems, more information, and the interactive check...

This site provides an image of M.C. Escher's lithograph, "Convex and Concave," which can be enlarged by clicking on it. Included is a brief quote, "from the text of M.C. Escher - the Graphic Work," which provides some insight into...

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

[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.

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...

Polygons for kids. Learn how they work, terms, tricks and examples. Regular, convex, concave, complex, and more.