- Did you need to use the ruler to measure the length of each
(No. The ruler was only needed to measure the lengths of one
long and one short tube. These two tubes could then be used as
templates from which to obtain the measures for the remaining
- What was the basic geometric shape of this frame? (Triangle)
- What other shapes did you observe?
(Pentagons, rhombus, hexagons)
- What was the maximum number of tubes that came together at any
Think About It
would increasing the number of component triangles affect the shape
of the dome?
(The more triangles that are used, the closer the shape resembles
a true sphere.)
The plans for building a geodesic dome are scalable. In fact, you
can use the steps above to build versions using either plastic straws
or wooden toothpicks. Suppose you needed to scale the measurements
to straws that are 20 cm long. If you opted to use the uncut length
of the straw as the longer rod, what length would the shorter one
need to be cut to? Explain.
(Using the ratio 26:24, we uncover a proportionality constant
of about 0.92. When you multiply the 20 cm length by the constant,
you arrive at a length of about 18.5 cm for the shorter support.)
Geodesic Dome Advantages
Compare and contrast a geodesic dome design with a more traditional
dome built from reinforced cement. Think about the advantages of
the geodesic style. What are the advantages in material simplicity?
(You need only three basic parts: two lengths of pipe and a connector.)
What are the advantages in illumination?
(The open frame allows daylight to spill into the dome)
are the advantages in placing and lifting supports?
(The basic parts of the dome are relatively light)