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| Math Central | Quandaries & Queries |
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Question from jacques, a student: A football stand 150 yd long has 20 tiers of seats; each tier has a rise of 2ft and tread of 3ft.Its construction of reinforced concrete with a cross section as shown. Find the amount of the material used in its construction. |
Jacques,
You didn't send a drawing of the cross section but I expect it looks like this. (Mine only has 5 tiers.)
The volume of concrete needed is the area of the cross section times the length of the stand which is 150 yards. To find the area of the cross section I would draw a second copy,
and then turn it 180 degrees and put it on top of the first copy.
What is the area of this rectangle?
Penny
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