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Old 07-18-2007   #1
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Default Geometry Help?

Two pyramids are similar with a ratio of surface areas of 25:64, Find the volume of the second pyramid given the first has a volume of 250m^3.thanks in advance.ania: when I did it your way i got 16....and i dont think that's it.doctor Q: i've never done it your way before
Old 07-18-2007   #2
Doctor Q
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First we take the ratio-: 25:6464 / 25 = 2.56Now we cube this amount to allow for the change in area in the three axis (x,y,z)2.56^3 = 16.777216Now we multiply the 1st surface area by this....250 x 16.777216 = 4194.304 m^3NOTE!!! Now I've seen Mathmatica's way, I think he's got it correct.
Old 07-18-2007   #3
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To do this you need to find the scale factor, a:b, by square rooting the surface areas. It is 5:8.Then you set up a proportion a^3:b^3=Volume1/Volume 2Cross multiply and solve.

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