uses crt;

var a,b,c:real;

begin

clrscr;

readln(a,b,c);

writeln(a+b+c:4:2);

readln;

end.

uses crt;

var a: integer;

begin clrscr;

Writeln('Nhap vao do dai canh cua tam giac deu: '); readln(a);

Writeln('Chu vi cua tam giac deu do la: ',a*3);

readln;

end.

Var r,s,c:real;

Begin

Write('Ban kinh = ');readln(r);

s:=3.14*r*r;

c:=2*3.14*r;

Writeln('Dien tich la ',s:10:2);

Write('Chu vi la ',c:10:2);

Readln

End.

2: 

#include <bits/stdc++.h>

using namespace std;

double a,b,c,p,s;

int main()

{

cin>>a>>b>>c;

p=(a+b+c)/2;

s=sqrt(p*(p-a)*(p-b)*(p-c));

cout<<fixed<<setprecision(2)<<s;

return 0;

}

uses crt;

var a:integer;

begin

clrscr;

readln(a);

writeln(a*4);

writeln(a*a);

readln;

end.

Input của chương trình là gì bạn nhỉ?

Program Dien_tich_tam_giac;
Var
a,b,c:Integer;
p,s:Real;
Begin
Writeln('DIEN TICH TAM GIAC');
Writeln('------------------');
Write('-Nhap so thu nhat: ');
Readln(a);
Write('-Nhap so thu hai : ');
Readln(b);
Write('-Nhap so thu ba : ');
Readln(c);
If (a+b>c) And (b+c>a) And (c+a>b) Then
Begin
Writeln('+Dung la Tam giac');
p:=0.5*(a+b+c);
s:=Sqrt(p*(p-a)*(p-b)*(p-c));
Writeln('+Dien tich= ',s:10:2);
End
Else
Writeln('+Khong phai la Tam giac');
Writeln;
Writeln(' Bam phim <Enter> de ket thuc');
Readln
End.

#include <bits/stdc++.h>

using namespace std;

double p,a,b,c,cv,s;

int main()

{

cin>>a>>b>>c;

cv=a+b+c;

p=cv/2;

s=sqrt(p*(p-a)*(p-b)*(p-c));

cout<<fixed<<setprecision(2)<<cv<<endl;

cout<<fixed<<setprecision(2)<<s;

return 0;

}