Activities Index | Handout | Educator Ideas
http://www.pbs.org/wgbh/buildingbig/educator/act_geodesic_ei.html
Time
60–90 minutes
(depending on number of participants)

Materials
(for the whole group)
• many newspapers
• measuring tape
• masking tape (colored, if possible)
• markers, glitter, beads, and glue for decorating, if desired
• hand wipes for cleanup

Video Connection
Before the activity, show "Geodesic Domes" from Domes to introduce domes constructed from triangles. (See the Program Description to locate the show segment.)

See Dome Overview.

For more information, see Additional Resources.

Icebreaker
• Have kids form domes by bending a few sheets of newspaper into a bowl shape. They will quickly note that the domes cannot support much of a live load. Then show kids the video segment suggested above or pictures of geodesic domes (such as Epcot Center in Orlando). Ask: What shapes do you notice in these domes? Why do you think these shapes were used? (Triangles; they are a stable shape because compression acting at one joint is balanced by tension along the opposite side.)
• Have kids build miniature geodesic domes using gumdrops and toothpicks. Let them experiment on their own or direct them to build the model shown here.

Lead the Activity
• Rolling the newspapers and measuring the tubes is time-consuming. This activity works best with large groups, so that each kid is only rolling a few tubes. Assign at least one adult "foreperson" to coordinate the dome assembly. Have kids decorate their tubes and attach them to the growing dome with an adult's help.
• The dome's joints are weak spots. Use plenty of tape to reinforce them.
• For safety, remind kids not to climb on the completed dome. Test the dome's strength by loading the top with magazines.

The Big Idea

A dome must support its own dead load as well as the live load of wind, rain, snow, or ice. The geodesic dome's strength is due to the fact that triangles are very stable shapes. It is difficult to distort a triangle; compression at one joint is balanced by tension along the opposite side (see Straw Shape). The geodesic dome's design distributes loads over all of the different triangles that comprise it.

Build on It
Possible outcome: Kids may add tension rings around the bottom of the dome or divide some or all of the triangular panels into smaller triangles.

Make Connections
Math Triangles are a shape that can be tesselated, or arranged to form a tiling pattern. Have kids predict what other shapes can be tesselated (hexagons, squares). Kids can cut the shapes out of paper and test their predictions.