Khối lăng trụ ABC.A'B'C' có thể tích V khi đó

* Hướng dẫn giải

Đáp án A

Ta có: $V=S_{A\text{'}B\text{'}C\text{'}}.d\left(A,\left(A\text{'}B\text{'}C\text{'}\right)\right)$ 

Mà $V_{A.A\text{'}B\text{'}C\text{'}}=\frac{1}{3}{S}_{A\text{'}B\text{'}C\text{'}}.d\left(A,\left(A\text{'}B\text{'}C\text{'}\right)\right)=\frac{1}{3}V$

$\Rightarrow V_{A.BCB\text{'}C\text{'}}=V-V_{A.A\text{'}B\text{'}C\text{'}}=V-\frac{1}{3}V=\frac{2}{3}V$