The answer is:  [A]:  "right [triangle]" .
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Explanation:
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Given:  Side lengths:
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  " 24 in., 32 in., and 40 in " ;  
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Divide each side length by "8" ; 
24 in. / 8 = 3 in. ; 
32 in. / 8 = 4 in. ;  and
 
40 in. / 8 = 5 in. . 
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3 in . , 4, in,  5 in. ;  is a "right triangle" ; 
since:  3² + 4² = 5² ;
→  9 + 16 = 25 ; 
according to the Pythagorean theorem:  " a² + b² = c² " .
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