document.write( "Question 1207323: For a ballet production, a truncated pyramid is constructed with a square base of 10 meters on a side, a height of 8 meters and a summit height of 2 meters. What is the total area of the surfaces of the truncated pyramid? \n" ); document.write( "
Algebra.Com's Answer #845144 by greenestamps(13334)\"\" \"About 
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\n" ); document.write( "The problem as stated is nonsense, since we don't know what \"summit height\" of 2 meters is.

\n" ); document.write( "It is a good problem if we assume that the 2 meters is supposed to be the length of a side of the square top of the truncated pyramid. So I'll go ahead with that assumption.

\n" ); document.write( "Consider the pyramid before it was truncated.

\n" ); document.write( "Use similar triangles and the given dimensions to determine that the height of the original pyramid was 10m.

\n" ); document.write( "The slant height of a face of the original pyramid (peak to midpoint of a side of the base) is the hypotenuse of a right triangle with legs 5m and 10m:

\n" ); document.write( "\"h=sqrt%285%5E2%2B10%5E2%29=sqrt%28125%29=5sqrt%285%29\"

\n" ); document.write( "The area of each triangular face of the original pyramid is (one-half base times height)

\n" ); document.write( "\"A=%281%2F2%29%2810%29%285sqrt%285%29%29=25sqrt%285%29\"

\n" ); document.write( "The area of each face of the small pyramid that was cut off to form the truncated pyramid is

\n" ); document.write( "\"A%2B%281%2F2%29%282%29%28sqrt%285%29%29=sqrt%285%29\"

\n" ); document.write( "So the area of each face of the truncated pyramid is

\n" ); document.write( "\"25sqrt%285%29-sqrt%285%29=24sqrt%285%29\"

\n" ); document.write( "The total surface area of the truncated pyramid is the area of the two bases, plus the area of the four faces:

\n" ); document.write( "\"%28100%2B4%29%2B4%2824sqrt%285%29%29=104%2B96sqrt%285%29\"

\n" ); document.write( "ANSWER: \"104%2B96sqrt%285%29\" square meters

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