Cho hình chóp
với tam giác
vuông cân tại
,
,
và
. Trên cạnh
lấy điểm
sao cho
.Tính thể tích tứ diện
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img1.png)
![img2](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img2.png)
![img3](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img3.png)
![img4](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img4.png)
![img5](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img5.png)
![img6](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img6.png)
![img7](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img7.png)
![img8](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img8.png)
![img9](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img9.png)
![img10](https://cungthi.online/upload/questionbank3/eduquestion/201735301515321327/obj201735301515321327668322_images/obj201735301515321327668322_img10.png)
A.
.
B.
.
C.
.
D.
.
Đáp án và lời giải
Đáp án:A
Lời giải:
Tam giác ABC vuông cân B nên
.
Do đó . Vì
nên
là chiều cao của hình chóp
.
Suy ra .
Ta có;.
Suy ra .
Vậy đáp án đúng là: A.