SOLUTION: find what fraction of the altitude of a tetrahedron must be cut off by a plane parallel to the base of the tetrahedron such that the volume of the cut off tetrahedron is one third

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Question 1088524: find what fraction of the altitude of a tetrahedron must be cut off by a plane parallel to the base of the tetrahedron such that the volume of the cut off tetrahedron is one third of the original volume.
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
Compared to the original tetrahedron, the smaller tetrahedron cut off is a similar shape, meaning a scaled-down version.
For similar shapes, the ratios of lengths (L and l), surface areas (A and a), and volumes (V and v) are related by
v%2FV=%28l%2FL%29%5E3 and a%2FA=%28l%2FL%29%5E2 .
In this case, if x is the fraction of the altitude of a tetrahedron cut off by a plane parallel to the base of the tetrahedron,
and the volume of the small cut off tetrahedron is one third of the original volume,
1%2F3=x%5E3 --> x=root%283%2C1%2F3%29=root%283%2C9%2F27%29=root%283%2C9%29%2F3=about0.693 .
The exact result is an irrational number, so it cannot be expressed as a fraction.
However, the fractions 52%2F75 and 658%2F949 are good approximate values.