ROLLING BRIDGE DESIGN
Tasks adapted from Burger, E. B., Chard, D. J., Kennedy, P. A., Leinwand, S. J., Freddie, R. L., Roby, T. W., … Waits, B. K. (2012). Geometry, (p. 671). Houghton Mifflin Harcourt.
Design a rolling bridge made of four isosceles trapezoidal sections with 45 degree base angles. When opened the trapezoidal sections close together to form a square.
Two scenarios exist for the design:
1st Scenario - the bridge open sequentially such that B1 alone closes upon B2, followed by B3 & B4 closing upon B2 and so on until the bridge is fully opened.
2nd Scenario - the bridge opens simultaneously such that all sections open at the same time (B1, B2, B3, B4 all move as one unit).
In your summary, please include:
• A sketch of the bridge including angle measures and lengths. For the sequential approach, sketch the bridge at each stage. For the simultaneous approach, sketch the bridge at
0°, 30°, 45°, 60°, and 90°.
• Plot the path of the point K for each approach.
• When completely ‘rolled’ up into the square, how tall is the bridge structure?
• What are the limitations to this bridge design? What are its strengths?