This in-depth paper examines the idea of convexity. Euclid's Elements, the first geometry textbook, assumed convexity without mentioning the term.

The text of the policy of sustained reprisal from "The Pentagon Papers," covers introductory remarks, an outline of the policy, the expected effect of sustained reprisal policy, and present action recommendations.

Resource presents President Bush's reaction and speeches after the September 11, 2001terrorist attacks in New York City and the Pentagon in Washington.

This site has a comprehensive overview of the September 11, 2001 attacks on the U.S., including information on Osama bin Laden's background, the formation of Al Qaeda, the attacks themselves, the US response, civil liberties and national...

Comprehensive web page that offers a plethora of outstanding resources for one who is studying the 9/11 terrorist attacks.

Part of an extensive website from the Council on Foreign Relations devoted to understanding all aspects of terrorism and its implications for the United States, this section deals with defining and understanding the different types of...

In this video segment [2:01] from Cyberchase, the CyberSquad finds that by arranging triangle tiles they are able to create a path that will allow them to cross a river of hot lava.

This site from The History Place is a comprehensive site about the events leading up to the Vietnam War and ending with the withdrawal of American troops. Excellent slide show with an array of images from the era.

Impressive web site on the events of September 11, 2001, by CNN. Most of the information is accessible without a subscription, but there are a few video links that require a subscription. Excellent resource!

This interactive web lesson teaches students about two-dimensional shape attributes.

An excellent online resource that contains a large collection of links to speeches and rhetorical artifacts all pertaining to September 11, 2001, terrorist attacks on America. Presented in a timeline of events with material in audio,...

Site provides information on Bin Laden -- his life story and his terrorist organization. Site also relates the trail of warnings that led to 911. Student can play a video of an early interview with Bin Laden.

Watch minute by minute coverage of the events of 9/11 and the week following, from 20 television news agencies around the world. The site also offers analysis of the news coverage by several scholars. From the top navigation bar, choose...

A biography of Neil Sheehan, a journalist who won the Pulitzer Prize for Non-Fiction for a book he wrote about his experience of the Vietnam War. Includes a profile, videos, and a photo gallery.

The 1960's was a time of upheaval in America mainly led by young adults disenchanted with the government. Examine the influences of this movement and read an excerpt from the Port Huron Statement written by the SDS at the University of...

Official website of Daniel Ellsberg. Many links, including a biography, interviews, and articles he has written.

This resource provides a practice geometry quiz for students to use.

This site presents a collection of screenshots from over 200 news sites taken on September 11th and 12th and serves to provide an accurate representation of what material was produced as the tragedy unfolded. Click on a screenshot to see...

Introduces the concept of regular polygons along with regular polygon examples, not regular polygons, irregular polygons, and area of a regular polygon. Check-out the solved examples for better understanding and try your hand at solving...

Generate different "nets" for paper construction of common three-dimensional shapes: cube, cuboid, pyramid, cone, tetrahedron, cylinder, octahedron, rhombic prism, dodecahedron, pentagonal prism, and pentagonal prism.

Learn what an interior angle of a polygon is and how you can calculate their value in triangles, quadrilaterals, and pentagons. Includes a chart that overviews the "general rule" for determining the sum of internal angles in any polygon...

[Free Registration/Login Required] Students will move the pentagon points to explore convex polygons. Click learn more to watch a video and click challenge me to answer a practice question.

The 'Platonic solids' are three-dimensional shapes formed by putting together identical regular faces. Every corner and every edge is identical to every other corner and edge. There are five such 'solids': the tetrahedron, cube,...

Practice identifying quadrilaterals, pentagons, hexagons, and octagons. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video tutorial, or receive hints.