DEF is indeed similar to ABC. Sides 4.5, 15, & 16.5 are 1.5 times their corresponding sides 3, 10, & 11. (GHI is equilateral, and therefore not similar)
["<code style=\"display: none; \">DEF</code>"]
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I think the student is correct. I'm guessing the question was intending to choose sides so that the triangles are not similar, but accidentally selected a triangle that is similar when flipped.
Fix side comparisons #15880 #16083 #14336 #15704
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