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Tetrahedron bounded by spheres (Posted on 2003-04-17) Difficulty: 3 of 5
A regular tetrahedron holds a sphere snugly within its four sides. A larger sphere surrounds the tetrahedron, just touching its four vertices. What is the ratio of radii of the two spheres?

See The Solution Submitted by Bryan    
Rating: 3.5000 (6 votes)

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I get | Comment 3 of 7 |
Rad inner = (1/2)tan30 ==> sin30/2cos30
Rad outter = (1/2cos30) ==> 1/2cos30

Dropping denoms, it's "sin30:1" or like Hank said "1:2"

  Posted by jude on 2003-04-17 09:41:56
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