Pravilni tetraedar
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smješten je u kocku
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stranice duljine
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tako da točka
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leži u ravnini
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. Odredi udaljenost točaka
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i
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.
%V0
Pravilni tetraedar $ABXY$ smješten je u kocku $ABCDABCD$ stranice duljine $1$ tako da točka $X$ leži u ravnini $ABCD$. Odredi udaljenost točaka $Y$ i $A$.