How to Make Geodesic Domes With Toothpicks & Gumdrops

Geodesic dome structures are stronger than traditional square buildings.

According to the National Council of Teachers of Mathematics, Buckminster Fuller is credited with constructing the first geodesic dome. Geodesic domes are strong, efficient sphere-like structures composed of triangles. The designs of geodesic domes vary. Geodesic domes that have greater numbers of small triangles have greater frequency. Geodesic domes with greater frequency are able to closely approximate the shape of a sphere. Geodesic domes that approximate a spherical shape combine the strength of a sphere with the stability of a triangle. Creating a model of a geodesic dome made with toothpicks and gumdrops is fun and easy.

Things You'll Need

• 11 gumdrops
• 25 toothpicks

Instructions

1. Select a gumdrop. Insert five toothpicks into the gumdrop to form a star pattern. Add a gumdrop to the end of each of the five toothpicks. The center gumdrop is the apex, or highest point, of this geodesic gumdrop dome.

2. Connect the five gumdrops that are on the ends of the star pattern together with toothpicks to form what looks like a pentagon. This makes up the top of the geodesic gumdrop dome. The sides of the pentagon will serve as the base for five equilateral triangles.

3. Construct an equilateral triangle on one of the pentagon sides using two toothpicks and a gumdrop. Construct four more equilateral triangles in the same way on the four remaining sides of the pentagon. The distinctive arrangement of triangles in the geodesic dome helps to evenly distribute the forces of tension and compression on the structure. According to experts at Exploratorium, triangles are able to balance these forces because their angles cannot be changed without shortening (breaking) one or more of the sides.

4. Connect the gumdrop tops of the five triangles with the five remaining toothpicks. This is the base of the geodesic dome. The sides of the pentagon will serve as the base for five equilateral triangles. Steven Reed, a teacher from the Kyrene School District in Arizona, says geodesic domes constructed from equilateral triangles are single frequency domes and are not as strong as multiple frequency domes.

References

• National Council of Teachers of Mathematics: A Treasure Trove of Triangles
• Exploratorium: Geodesic Gumdrops: Make Amazing Architecture with Candy and Toothpicks
• Kyrene School District No: 28: Geodesic Dome

Resources

• Edmark: Geodesic Domes
• National Building Museum: Fuller's Fantastic Geodesic Dome
• PBS Kids: Gumdrop Dome
• Teachers' Domain: Triangles: Testing the Strength of a Gumdrop Dome