Cho hình lăng trụ đứng
có đáy
là tam giác vuông tại
,
, mặt phẳng
tạo với đáy một góc
và tam giác
có diện tích bằng
. Tính thể tích khối lăng trụ
.
A.A :
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096941866_images/obj2018030958854796096941866_img1.png)
B.B :
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096560944_images/obj2018030958854796096560944_img1.png)
C.C :
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096431035_images/obj2018030958854796096431035_img1.png)
D.D :
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096301125_images/obj2018030958854796096301125_img1.png)
Đáp án và lời giải
Đáp án:D
Lời giải:Phân tích:
V= Bh = SABC.A’B’C’.AA’.
Do
.
Và
Ta có:
.
![img6](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096381646_images/obj2018030958854796096381646_img6.png)
.
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096381646_images/obj2018030958854796096381646_img1.png)
![img2](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096381646_images/obj2018030958854796096381646_img2.png)
![img3](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096381646_images/obj2018030958854796096381646_img3.png)
![img4](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096381646_images/obj2018030958854796096381646_img4.png)
![img5](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096381646_images/obj2018030958854796096381646_img5.png)
![img6](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096381646_images/obj2018030958854796096381646_img6.png)
![img7](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2018030958854796096/obj2018030958854796096381646_images/obj2018030958854796096381646_img7.png)