cạnh dáy là

14 : 2 x 3 = 21m

diện tích cái ao là

21 x 14 : 2 = 147m2

Trong không gian Oxyz, cho ba điểm A, B, C lần lượt thuộc các tia O x ,   O y ,   O z  (không trùng với gốc tọa độ) sao cho O A = a ,   O B = b ,   O C = c .  Giả sử M là một điểm thuộc miền trong của tam giác ABC và có khoảng cách đến các mặt O B C , O C A , O A B  lần lượt là 1, 2, 3. Tính tổng S = a + b + c  khi thể tích của khối chóp O . A B C  đạt giá trị nhỏ nhất

A. S = 18

B. S = 9

C. S = 6

D. S = 24

Today, i interviewed my classmates about actors or actresses they like best. Each person has a different idea. Ha, Anh, Trinh love some actresses such as Bao Thanh, Minh Hang, Nha Phuong. But Minh Duc, Ha Anh, Ngoc Anh like some actors such as Toki, K.O, Tung Maru. They are members of Uni5. All of my friends are interested in young actors and actresses. Most of friends who i interviewed like young and experienced people. And no one enjoys foreign ones. That is the result of mine .

Hoa's mom hopes Hoa will be well .

Hoa's parents work hard on the farm because it is nearly harvest time .

Hoa's mom received a letter from Hoa's aunt last week .

Hoa's aunt wrote a lot about her. They were good .

Hoa takes morning excercise these days .

Hoa never liked to get up early when she was in Hue .

Hoa's parents will visit her in Ha Noi after the harvest .

Hoa is glad to hear her parents are well .

Hoa's friends also hope to meet Hoa's parents in Ha Noi .