Google Voyager Stories: Quadrilaterals, Part 2

In this exploration, we will continue analyzing quadrilaterals, this time focusing on parallelograms and trapezoids. We once again start with Stonehenge to look at post and lintel construction, then we visit the Puerta de Europa towers in Madrid, Spain. Each structure is an application of the geometric principles behind quadrilaterals. There is a companion Google Earth exploration found at this link (best viewed in Chrome).

To see the complete collection of Google Earth Voyager Stories from Media4Math, go to this link.

1. Introduction to Quadrilaterals: Stonehenge

To start this lesson, watch this video about Stonehenge, which is an example of post and lintel construction. This is also an example of a basic quadrilateral form used in many architectural structures. You'll see the connection between this ancient structure and the towers in Madrid.

2. The Geometry of the Puerta de Europa Towers

Watch this video clip to learn about the Puerta de Europa towers and how they use rectangular shapes.This segment reviews the concept of center of gravity.

The following geometric concepts are introduced:

• Properties of parallelograms
• Diagonals of a rectangle
• Adjacent angles
• Supplementary angles

3. Constructing a Parallelogram with the TI-Nspire

In this video construct a parallelogram using the TI-Nspire graphing calculator. All keystrokes are clearly shown for constructing this type of figure.

The following geometric concepts are introduced:

• Parallelograms
• Parallel sides
• Side length
• Angle measures

4. Center of Gravity and Trapezoids

In this video continue the analysis of the Puerta de Europa's parallelogram structure. We then look at the trapezoidal shapes that make up the towers.

5. Conclusion

Some concluding observations on the Puerta de Europa towers.