Đáp án:
$C. \, \dfrac{V}{2}$
Giải thích các bước giải:
Ta có:
$S_{ABC} = \dfrac{1}{2}S_{ABCD}$
$\Leftrightarrow \dfrac{1}{3}S_{ABC}.d(S;(ABC)) = \dfrac{1}{2}.\dfrac{1}{e}S_{ABCD}.d(S;(ABCD))$
$\Leftrightarrow \dfrac{1}{3}S_{ABC}.d(S;(ABCD)) = \dfrac{1}{2}.\dfrac{1}{3}.S_{ABCD}.d(S;(ABCD))$
$\Leftrightarrow V_{S.ABC} = \dfrac{1}{2}V_{S.ABCD}$
