<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
Skip Navigation
Our Terms of Use (click here to view) have changed. By continuing to use this site, you are agreeing to our new Terms of Use.

Quadrilateral Classification

Categories of quadrilaterals based on sides and angles.

Atoms Practice
Estimated5 minsto complete
Practice Quadrilateral Classification
This indicates how strong in your memory this concept is
Estimated5 minsto complete
Practice Now
Turn In
Traveling on Trapezoids

Credit: Patrick Feller
Source: http://www.flickr.com/photos/nakrnsm/10145671373/
License: CC BY-NC 3.0

Have you ever seen a railroad bridge shaped like a trapezoid? These bridges, called truss bridges, were invented in the 1840s. Even when bridge manufacturers switched from wood to iron, they kept building truss bridges. They're still very popular today.

Old Faithful

Truss bridges are an efficient and reliable way to span short distances. They use a system of triangular supports to spread forces across the whole bridge. This gives them the ability to bear heavy loads, such as trains filled with freight, without breaking. Truss bridges are also very rigid. They don't bend or twist in high winds. They last for years with very little maintenance, and they can be built off-site and transported to wherever they're needed. There are quite a few varieties of truss bridges, but most were designed in the United States during the 1840s and 1850s. Companies competed to build the safest, strongest bridges. Historians classify the bridges based on how the triangular supports fit together. While the bridges were originally made of wood or iron, most truss bridges today are built from steel.

Credit: Erin Kohlenberg
Source: http://www.flickr.com/photos/erinkohlenbergphoto/5531056968/
License: CC BY-NC 3.0

On some truss bridges, vehicles travel across the top of the trapezoid. On others, they travel across the bottom. Some designs, like the one pictured above, use alternating trapezoids to allow truss bridges to span greater-than-normal distances.

See for yourself: http://science.howstuffworks.com/engineering/civil/bridge4.htm

Explore More

Visit the links below to see more trapezoidal truss bridges, learn about the different varieties, and find out what caused the unfortunate collapse of a truss bridge in Washington.




Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes
Please to create your own Highlights / Notes
Show More

Image Attributions

  1. [1]^ Credit: Patrick Feller; Source: http://www.flickr.com/photos/nakrnsm/10145671373/; License: CC BY-NC 3.0
  2. [2]^ Credit: Erin Kohlenberg; Source: http://www.flickr.com/photos/erinkohlenbergphoto/5531056968/; License: CC BY-NC 3.0

Explore More

Sign in to explore more, including practice questions and solutions for Quadrilateral Classification.
Please wait...
Please wait...