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Old 06-13-2007, 05:16 AM   #1
Tim McFarland
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This is actually an equipment question...

I'm working on building a 20" plyo box using Lincoln Brigham's plans, which are excellent. The angle cuts are at 10 degrees.

Assuming I want a 24" box, how long should I make the slanted side?

Or another way to put it - I know the length of the vertical side of this triangle, but I don't know the length of the horizontal side or the hypoteneuse. I know the top angle has to be 10 degrees, the right angle is 90 of course, which means the other angle has to be 80 degrees. How do I use the length of the one side and the angles to determine the length of the hypoteneuse?
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Old 06-13-2007, 06:01 AM   #2
Chris Kemp
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Tim, if you know the length of the slanted side for the 20" box you could just multiply that by 24/20 (1.2) to give you the length of the angled side for the bigger box.

Otherwise, I'm gonna have to try and remember my high scool trig and that could get ugly ...

Cheers, kempie
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Old 06-13-2007, 06:22 AM   #3
Karin Jonczak
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cheif "sohcahtoa"

Sin = opposite/hyp
Cosin = adjacent/hyp
T(something or other... its been 15 years) = opposite/adjacent

not bad for 15 years, :-)

K
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Old 06-13-2007, 06:24 AM   #4
Karin Jonczak
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I am not going to edit... I think I am too funny (as in, I made a funny mistake!)

its sinE not sin.... DOH

(and the other is tangent, looked it up)
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Old 06-13-2007, 08:03 AM   #5
Lincoln Brigham
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Questions like these are why one should make a cardboard mockup first! And don't forget to allow for the thickness of the plywood and the rubber on top!

But I think the short answer is 24.37 inches. I could be wrong. Make a cardboard mockup.

It's been 33 years since high school geometry and I still carry the trauma.

Did I mention you should build a cardboard mockup first?
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Old 06-13-2007, 08:35 AM   #6
John McEneany
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Or just make a cube shaped box!
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Old 06-13-2007, 08:35 AM   #7
Rob Izsa
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In a keep it simple way, the length of the sides will be determined by the size of the base and top. If your top is 18" and the base is 24", then just connect the dots and measure. Sounds simple on paper.
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Old 06-13-2007, 09:17 AM   #8
Lincoln Brigham
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Exactly. Cardboard IS paper....
Did I mention building a cardboard mockup? It's a wonderful sanity check.
Measure twice, cut once.
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Old 06-13-2007, 10:34 AM   #9
John Seiler
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If Lincoln were here he would recommend making a cardboard mockup.

I would second that.

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Old 06-13-2007, 02:28 PM   #10
Thomas Covington
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Pythagorean Theorum

a^2 + b^2 = c^2

a = height of the box
b = distance between the edge of the top and the edge of the bottom on the ground
c = the side in question
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