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12162010, 06:57 AM  #1 (permalink) 
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Calling all Mathmeticians..Need some help with angles
Can anyone confirm this? I'm trying to find the angles of stairs for my drop in. It's 10 feet tall, with 12 ladder stairs. It's been awhile since i've had to use geometry.

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12162010, 07:35 AM  #4 (permalink)  
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Quote:
I assume that you want the angles from predetermined/built lengths. So, using cos then taking the bottom right angle first, cos(x) = adjacent/hypotenuse > cos(x) = 6.6/12 > using inverse cosine, the bottom angle should be 56.63 degrees. Then, taking the top left angle, using cos(x) = adj/hypotenuse > cos(x) = 10/12 > inverse cosine, the top angle is 33,56 degrees, 33.56+56.53 = 90.09, so the angles match with the lengths Last edited by rainboarding; 12162010 at 07:42 AM. Reason: effed my math up. oops. 

12162010, 07:43 AM  #5 (permalink) 
Drunk with power...er beer.

A quick application of pythagoras says that the sides at 10, 6.6 and 12 are almost exactly correct. I don't have a calc with trig functions in front of me, so I can't confirm the actual angles.
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12162010, 08:16 AM  #7 (permalink) 
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Recall from trigonometry (not geometry) the mnemonic "SOH CAH TOA."
sin theta = opposite/hypotenuse sin theta = 10/12 sin theta = 0.83 calculator.com  Online Scientific Calculator Checks out. 
12162010, 04:07 PM  #10 (permalink) 
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Location: massachusetts
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Mathematically that would work out but practically I think you would want 90+45+45 so you have a better down ramp also if you increase your drop angle the length on the bottom must increase hopefully that made sense and for your third side the Pythagorean theorem A^2+b^2=c^2 should help
Last edited by bostonboarder; 12162010 at 04:09 PM. 
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