Question 645609
Which one of the following could not represent the lengths of the sides a right triangle?

A. 5, 12, 13
B. 2, 2, 2{{{ sqrt (2) }}}
C. 1, {{{sqrt (3) }}}, .2
D. 1, 2, 3
E. 6, 8, 10
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The length of the longest side has to be:
less than the sum of the other 2, and 
more than the difference between the other 2.
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A. 5, 12, 13
The longest side (12-5) < s < (12+5)
7 < s < 17
13 is between, so A is a triangle.