Nad stranicama
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,
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,

, kvadrata
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konstruirani su s vanjske strane jednakostranični trokuti
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,
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,
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. Odredite, kao funkciju duljine
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stranice kvadrata, volumen tijela koje nastaje rotacijom lika

oko pravca
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.
%V0
Nad stranicama $\overline{BC}$, $\overline{CD}$, $\overline{DA}$, kvadrata $ABCD$ konstruirani su s vanjske strane jednakostranični trokuti $BCE$, $CDF$, $DAG$. Odredite, kao funkciju duljine $a$ stranice kvadrata, volumen tijela koje nastaje rotacijom lika $BECFDGA$ oko pravca $AB$.