Cho hình chóp tam giác đều
có
. Gọi
là trực tâm tam giác
,
. Kí hiệu
là thể tích khối chóp
. Tính tỉ số
.
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20174028494215751393/obj20174028494215751393751393_images/obj20174028494215751393751393_img1.png)
![img2](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20174028494215751393/obj20174028494215751393751393_images/obj20174028494215751393751393_img2.png)
![img3](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20174028494215751393/obj20174028494215751393751393_images/obj20174028494215751393751393_img3.png)
![img4](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20174028494215751393/obj20174028494215751393751393_images/obj20174028494215751393751393_img4.png)
![img5](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20174028494215751393/obj20174028494215751393751393_images/obj20174028494215751393751393_img5.png)
![img6](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20174028494215751393/obj20174028494215751393751393_images/obj20174028494215751393751393_img6.png)
![img7](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20174028494215751393/obj20174028494215751393751393_images/obj20174028494215751393751393_img7.png)
![img8](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20174028494215751393/obj20174028494215751393751393_images/obj20174028494215751393751393_img8.png)
A.
.
B.
.
C.
.
D.
.
Đáp án và lời giải
Đáp án:A
Lời giải:
;
.
Vậy đáp án đúng là A.