# Similar Polygons and Scale Factors

## Polygons with the same shape, but not necessarily the same size.

Estimated7 minsto complete
%
Progress
Practice Similar Polygons and Scale Factors

MEMORY METER
This indicates how strong in your memory this concept is
Progress
Estimated7 minsto complete
%
Super Models

Credit: Samuel Zeller
Source: http://www.flickr.com/photos/zdepth/8217513543/

When an engineer designs a new car, how can she tell whether her design is efficient? Computer models can provide some information on how air flows around the car. However, airflow is complicated, and our computer models aren't perfect. And it's too expensive to build a full-sized prototype of the car to test. The solution? In the early stages of the design process, engineers use scale models to test airflow and wind resistance.

#### As Unpredictable as Weather

Air and water patterns are hard to model with computers. The U.S. Military instead creates physical models of ships and airplanes that are tested by scientists using wind and water tunnels. The tunnels allow the scientists to see how air and water flow over the models. These scale models are geometrically similar to the full-sized military vehicles.

Credit: NASA
Source: http://commons.wikimedia.org/wiki/File:MD-11_12ft_Wind_Tunnel_Test.jpg

Engineers can build models of natural features too. In Louisiana, engineers built a scale model of parts of the Mississippi River. The model shows how sediments flow down the river and how changes to the river affect the areas near its banks. They have used it to test ideas for restoring parts of the Mississippi Basin. Even though computers continue to get more powerful, engineers will depend on scale models for a long time.

#### Explore More

Not everything that engineers model becomes a reality. For instance, students from South Dakota recently built a very impractical airplane.

How did the model help the students test their ideas?

### Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes