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Introduction: 

Math is very important to bridge builders.  They need to know all the angles and measurements.  If they do not do their math right the whole bridge could collapse.

Task:

Two bridge builders are having an argument.

Jill: My bridge is longer than yours.  That means that it will use more pavement.
Jack: That's not true!  A short bridge can use just as much pavement as a longer one.
Jill: Yeah, right!  Longer bridges always need more pavement and that's a fact, Jack!
Jack: You wouldn't know a fact if it blew through your ears!

Oh, No! Why are they arguing?  Who is right and will Jack ever carry another pail of water?  Who do you think received the most brain damage from the fall?

You will have to examine a few bridges to see who is right.  Of course we all know that the amount of pavement is determined by the area of the bridge, right?

 Procedure:

  1. Examine at four bridges from the websites listed below.  Answer these questions in your notebook:

    1. What is this bridge called?

    2. Where is it located?

    3. What type of bridge is it?

    4. How long is the bridge?

    5. How wide is the bridge?

    6. Determine the area of the bridge.

  2. Your classroom will prepare a spreadsheet to show the relationship between the length and the area.  Enter your data into this spreadsheet.  Print out a graph to show the results.

  3. Examine the charts and graphs you have prepared.  Answer this question in your notebooks:

    1. Who was right?

    2. Does a longer bridge always use more pavement?

    3. Describe the relationship between the length and area of a bridge.

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