



 
Hi Rob. Pythagorus' theorem tells us that in a right triangle, the side lengths are related by c^{2} = a^{2} + b^{2} where c is the hypotenuse.
This form gives you the percentage size of the hypotenuse compared to the 12 inch base. For example, if you measure 6" for the height variable b, then sqrt(144 + 6^{2})/0.12 = 111.8 percent, so the hypotenuse is 111.8% of the base and hence you have to add 11.8% of the base measurement. If it is steeper, you should get a higher percentage. For example, if you measure the height as 8", you get: sqrt(144 + 8^2)/0.12 = 120.2 percent Hope this is useful to you.  


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