Building Bridges!!


 You are the chief architect for a major engineering firm.  The town of Mathville is interested in building a bridge with a truss structure.  Your boss wants to know how much it will cost to constrcuct the truss structures of the bridge.  However, the blueprints that the city planner has s ent you are incomplete.  Fill in the missing information by answering the following questions.  Feel free to use the diagrams provided and make sure you show all of your work to make your boss happy!


 

Assume that the top and bottom of the truss structure are parallel.  Also triangle ABC is the base pattern of the truss structure.  There will be 4 such triangles in the truss structure that you want to construct (as in the first diagram above) .

1.  y = 25 feet.  x = 30 feet.  What is the height of the truss structure?
 
 
 
 
 
 
 
 

2.  How long is the bottom beam of the structure?(The one that contains AC)  How long is the top beam of the structure?(The one that contains BD)
 
 
 
 
 
 
 

3.  We know that angle 1 and angle 2 are both 53 degrees.  What are the angle measures for the remaining angles in the second diagram?
 
 
 
 
 
 

4.  What geometric shapes are present in the truss structure?
 
 
 
 

5.  What is the area of the truss structure?  (Hint: what geometric shape is the truss?)
 
 
 
 
 
 
 

6.  If the price of steel is $400 per square foot how much would it cost two build one truss structure?
 
 
 
 
 
 

7.  The city planner has said that if your firm can build two truss structures for under $1.5 million that you would get the contract from the town.  Based on your answer in part 6 will your firm be the one building the bridge?
 
 












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