document.write( "Question 64953: My son is trying to find the length from the top left corner to the bottom right corner of a cube.\r
\n" ); document.write( "\n" ); document.write( "This is something I have not been taught, and have tried to find the formula on the internet, without success.\r
\n" ); document.write( "\n" ); document.write( "For example, how would this be done for a cube with the dimensions 3.3m x 1.7m x 1.7m\r
\n" ); document.write( "\n" ); document.write( "Regards\r
\n" ); document.write( "\n" ); document.write( "Gordon \n" ); document.write( "

Algebra.Com's Answer #45427 by 303795(602) $\"\"$ $\"About$

You can put this solution on YOUR website!
A cube has all 3 dimensions the same length so ( 3.3m x 1.7m x 1.7m) can't be a cube.
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\n" ); document.write( "This problem involves 3D but you need to consider only a 2D slice of it at a time. There are two steps to finding the solution.\r
\n" ); document.write( "\n" ); document.write( "First part is find the length diagonally across the base. Consider it as a square and use the Pythagorean Theorem to find the length.\r
\n" ); document.write( "\n" ); document.write( "The second part is to consider a slice taken from one top corner diagonally across to the opposite corner and slice through to the bottom of the cube. The diagonal on this rectangular slice is what you are trying to find. You calculated the length across the bottom in part one above and the vertical height is the side length of the cube. Again use the Pythagorean Theorem to find the desired length.\r
\n" ); document.write( "\n" ); document.write( "The general idea can be used on any rectangular prism. (including your square prism above). An answer of about 4.1 metres for your example would be correct. \n" ); document.write( "

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