Câu 1: 

#include <bits/stdc++.h>

using namespace std;

double a,b,c;

int main()

{

cin>>a>>b>>c;

cout<<fixed<<setprecision(2)<<(a+b+c)/3;

return 0;

}

nbbnbnbbnn\(\dfrac{^{ }}{ }\)

Program ba_canh_cua_tam_giac;

uses crt;

var a,b,c: real;

BEGIN

Write('nhap do dai canh a'); Readln(a);

Write('nhap do dai canh b'); Readln(b);

Write('nhap do dai canh c'); Readln(c);

If (a<(b+c)) and (b<(c+a)) and (c<(b+a)) then write('do la do dai cua mot tam giac')

else write('do khong la do dai cua mot tam giac');

Readln;

END.

Thanks

bạn ơi viết chương trình bằng chữ hay là ở trong pascal z bạn

Hình chữ nhật ở đâu vậy bạn?

uses crt;

const fi='bai1.inp'

var f1:text;

a,b,c,cv,dt,p:real;

begin

clrscr;

assign(f1,fi); rewrite(f1);

write('Nhap a='); readln(a);

write('Nhap b='); readln(b);

write('Nhap c='); readln(c);

if (a>0) and (b>0) and (c>0) and (a+b>c) and (a+c>b) and (b+c>a) then 

begin

cv:=a+b+c;

p:=cv/2;

dt:=sqrt(p*(p-a)*(p-b)*(p-c));

writeln(f1,'Chu vi la: ',cv:4:2);

writeln(f1,'Dien tich la: ',dt:4:2);

end

else writeln(f1,'Day khong la ba canh trong mot tam giac');

close(f1);

readln;

end.

#include <bits/stdc++.h>

using namespace std;

double a,b,c;

bool kt;

int main()

{

cin>>a>>b>>c;

if (a+b>c && b+c>a && a+c>b)

{

kt=false;

if (a==b && b!=c && a!=c) kt=true;

if (b==c && b!=a && c!=a) kt=true;

if (a==c && a!=b && c!=b) kt=true;

if (kt==true) cout<<"YES";

else cout<<"NO";

}

else cout<<"NO";

return 0;

}

Câu 1: 

uses crt;

var a,s,p:real;

begin

clrscr;

repeat

write('Nhap do dai canh hinh vuong:'); readln(a);

until a>0;

p:=4*a;

s:=sqr(a);

writeln('Chu vi hinh vuong la: ',p:4:2);

writeln('Dien tich hinh vuong la: ',s);

readln;

end.

Câu 2: 

uses crt;

var a,b,t,s,h:real;

begin

clrscr;

write('Nhap a='); readln(a);

write('Nhap b='); readln(b);

t:=a+b;

h:=a-b;

s:=a*b;

writeln('Tong la: ',t:4:2);

writeln('Hieu la: ',h:4:2);

writeln('Tich la: ',s:4:2);

readln;

end.

Câu 3: 

uses crt;

var a,b,c:real;

begin

clrscr;

repeat

write('Nhap a='); readln(a);

write('Nhap b='); readln(b);

write('Nhap c='); readln(c);

until (a>0) and (b>0) and (c>0);

if (a+b>c) and (a+c>b) and (b+c>a) then writeln('Day la ba canh trong mot tam giac')

else writeln('Day khong la ba canh trong mot tam giac');

readln;

end.

uses crt;

var a,b,c:real;

begin

clrscr;

repeat

write('Nhap a='); readln(a);

write('Nhap b='); readln(b);

write('Nhap c='); readln(c);

until (a>0) and (b>0) and (c>0);

if (a+b>c) and (a+c>b) and (b+c>a) then writeln('Day la ba canh trong mot tam giac')

else writeln('Day khong la ba canh trong mot tam giac');

readln;

end.