# Measuring

#1
07-05-08, 03:38 PM
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Join Date: Nov 2006
Location: Jersey
Posts: 526
Measuring

In high school we did an experiment that measured the height of a flag pole with a protractor, string and an nut using some kind of formula.

I need to determine the height of my chimney but don't feel like getting out the ladder.

Does anybody know what I am talking about and how this is done and what formula to use?

#2
07-05-08, 04:15 PM
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Join Date: May 2006
Location: Iowa!!!!!
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It's sort of the Pythagorean theorem which is A squared X B squared = C squared in a right triangle. A and B are usually the legs of the right triangle and C is the hypotenuse or the leg opposite the right triangle. Using that theorem, though, requires knowing the length of A and B.

However, you can use your string and extend it from the base of the chimney, in a level line, longer then the approximated height of the chimney, creating a 90 degree angle. Then sighting up from the string at a 45 degree angle to a point at the top of the chimney will give you a point on the string, which if measured to the base of the chimney = height of the chimney.

An easier way to do it would be to take an object of known height and measure the shadow it cast horizontal on a line 90 degrees to itself. Then measure the length of the shadow of the chimney in the same manner. Then divide the longer shadow by the shorter shadow and multiple that number by the height of the known height object = height of the chimney.

For example: A board 6 feet in vertical height casing a shadow of 4 feet horizontal (90 degrees to the board). The chimney is casting a shadow of 16 feet measured similarly. Then 16/4 = 4. Then 4 X 6 = a chimney height of 24 feet.

Or get the kids to get out the ladder.

#3
07-06-08, 07:05 AM
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Join Date: Nov 2006
Location: Jersey
Posts: 526
Thanks Marbobj, I'll probably get the ladder out.

BTW, I should have put this thread under the "General Chats and Discussions".

Sorry.

#4
07-06-08, 07:27 AM
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Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,673
Yeah, I usually just get out the ladder.

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