document.write( "Question 1136404: Given:
\n" ); document.write( "MK⊥LM, MK⊥KN
\n" ); document.write( "MN=13, KL=15, LM-KN=4
\n" ); document.write( "Find: Area of KLMN.\r
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Algebra.Com's Answer #754172 by greenestamps(13216)\"\" \"About 
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\n" ); document.write( "Since all the measurements are whole numbers, we can easily solve the problem by guessing, knowing that the side lengths of right triangles KMN and KML are Pythagorean triples.

\n" ); document.write( "Since MN=13, KN is almost certainly either 5 or 12. Trying KN=5 makes MK=12 and LM=9; and that makes triangle KML a Pythagorean triple 9, 12, and 15.

\n" ); document.write( "So triangle KMN is a 5-12-13 triangle with area (5*12)/2 = 30; triangle KML is a 9-12-15 triangle with area (9*12)/2 = 54.

\n" ); document.write( "Then the area of KLMN is 30+54 = 84.

\n" ); document.write( "The problem can be solved formally using the Pythagorean Theorem.

\n" ); document.write( "Let KN = x; then LM = x+4. And let KM = y. Then

\n" ); document.write( "\"x%5E2%2By%5E2+=+13%5E2+=+169\"
\n" ); document.write( "\"%28x%2B4%29%5E2%2By%5E2+=+x%5E2%2B8x%2B16%2By%5E2+=+225\"
\n" ); document.write( "\"8x%2B16+=+56\"
\n" ); document.write( "\"8x+=+40\"
\n" ); document.write( "\"x+=+5\"

\n" ); document.write( "Then the rest of the path to the answer to the question is the same as above.
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