Google Earth Voyager Story: Circular Structures, Part 1
In this exploration, we will explore circular structures and in the process discover the geometry of circles. We start with Pueblo Bonito in Chaco Canyon, New Mexico. This network of circular kivas will reveal some interesting properties of circular structure. To see the Google Earth version (on Chrome) of this lesson go to this link.
To see the complete collection of Google Earth Voyager Stories from Media4Math, go to this link.
1. Introduction to Circles: Pueblo Bonito
To start this lesson, watch this video about Pueblo Bonito, which consists of a network of circular structures called kivas. One of the features of circular structures is the ability to observe the sky from any angle. Ever wonder why observatories are circular in shape? Watch how Pueblo Bonito is an ancient celestial observatory.
The following geometric concepts are introduced:
- Center
- Radius
- Diameter
- Chord
- Intercepted arc
2. The Geometry of the Roman Colosseum
Watch this video clip to learn about the Roman Colosseum and how it uses circular arcs. Although the Colosseum is elliptical in shape, it was constructed from circular arcs pieced together smoothly to create the elliptical form. The next time you're at a football stadium, think about the circular structure of the architecture.
The following geometric concepts are introduced:
- Locus of points
- Definition of a circle
- Definition of an ellipse
- Focus/foci
- Radiu/radii
- Circular arc
3. Constructing a Model of the Roman Colosseum with the TI-Nspire
In this video construct a the circular framework for the Roman Colosseum using the TI-Nspire graphing calculator. All keystrokes are clearly shown for constructing this shape. Your final construction should look like this.
The following geometric concepts are introduced:
- Cartesian coordinate plane
- Line segments
- Midpoint
- Intersection point
- Tangent
- Slope
4. Building a 3D Model of the Roman Colosseum
In this video continue your exploration of circular structures by building a scale model of the Roman Colosseum with Lego blocks or other building materials. Using the geometric sketch you created in the previous exercise, you'll build a blueprint from which you can constructe the stadium portion of the Colosseum.
To see a step-by-step tutorial on the geometric construction, download and print this document.
You can also use this blueprint to begin building your model (but we recommend doing the geometric construction).
