The vote of king có nghĩa là lá phiếu của vua☺

Diện tích tăng \(\frac{5}{3}\)lần

Trả lời :

*Tự vẽ hình nhé b.

Xét \(\Delta ABC\)có : D là trung điểm AB, E là trung điểm AC

=> DE là đường trung bình \(\Delta ABC\)

=> DE // BC mà H, M \(\in BC\)=> DE // HM

=> DEMH là hình thang (1).

Xét \(\Delta ABC\)có : D là trung điểm AB, M là trung điểm BC 

=> DM là đường trung bình \(\Delta ABC\)

=>  \(DM=\frac{1}{2}AC\)(*).

\(\Delta\)vuông ACH có : \(\widehat{ACH}=90^o\), HE là trung tuyến

=> \(HE=\frac{1}{2}AC\)(**)

Từ (*) và (**) => DM = HE (2).

Từ (1) và (2) => DEMH là hình thang cân (đpcm).

program tim_tuoi;

uses crt;

var i,j,ngaysinh,tuoi, uoctuoi,k:integer;

begin

    clrscr;

    for i:=1 to 9 do

    for j:=0 to 9 do

    for k:=0 to 9 do

    begin

    uoctuoi:=sqr(i)+sqr(j)+sqr(k);

    tuoi:=i*100+j*10+k;for ngaysinh:=1 to 31 do

    if tuoi =uoctuoi+ngaysinh then write('tuoi cua cu la: ',tuoi);

    end;

    readln;

end.

con cach de hon khong

All of the special holidays in my country, I Tet the most. Tet is an occasion to everyone get together in warm atmosphere. Before Tet holiday, Everyone prepares many things and decorates their house. I plant a lot of flowers in front of my house and buy many things such as clothes, foods ...

Besides, most of the streets also are decorated beautifully with colorful lights and flowers. During Tet, I spends more time on visiting my relatives, friends and colleagues. Especially, I give to each other the best wishes for the new year. Tet is an opportunity for children receive lucky money. There is a funny thing that people try to avoid argument or saying any bad things at Tet. I love Tet holiday!

First, everybody has to do their share of the household chores. For example, my mother cooks meals everyday, my father mends things around the house in his free time, my elder sister washes clothes and I usually clean the house. Second, I and my sister have to prepare meals. I think so. Because, my mother cooks meals and we should help her. It is a service which we express deep gratitute to mom. And my father will be happy if the meals are ready on the table by the time he gets home. During the school year, I'm not allowed to watch TV or talk on the phone. My parents don't allow me to access the internet for amusement. In fact, I miss them, but I know my parents want me to concentrate on studying. It's good for me. Next, whenever problems come up, we must discuss them frankly and find solutions quickly, or before making an important decision. I had to be allowed by my parents.The most important rule is frankness. All members have to speak honestly so that we can believe in each other. All in all, family rules are necessary.

Nhớ đúng !