uses crt;

const fi='baitap.txt'

var f1:text;

a,b:integer;

begin

clrscr;

assign(f1,fi); reset(f1);

readln(f1,a,b);

writeln('Chu vi la: ',(a+b)*2);

writeln('Dien tich la: ',a*b);

close(f1);

readln;

end.

#include <bits/stdc++.h>

using namespace std;

long long a,b;

int main()

{

freopen("sn.inp","r",stdin);

freopen("cn.out","w",stdout);

cin>>a>>b;

cout<<a*b;

return 0;

}

uses crt;

const fi='dulieu.dat'

var f1:text;

a,b,p,s:array[1..100]of real;

i,n:integer;

begin

clrscr;

assign(f1,fi); reset(f1);

n:=0;

while not eof(f1) do 

begin

n:=n+1;

readln(a[n],b[n]);

end;

for i:=1 to n do 

  begin

p[i]:=(a[i]+b[i])/2;

s[i]:=a[i]*b[i];

end;

for i:=1 to n do 

  writeln(p[i]:4:2,' ',s[i]:4:2);

close(f1);

readln;

end.

const fi='hcn.txt'

fo='ketqua.txt'

var f1,f2:text;

a,b:array[1..100]of integer;

n:integer;

cv,dt:real;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

n:=0;

while not eof(f1) do

  begin

inc(n);

readln(f1,a[n],b[n]);

end;

for i:=1 to n do 

  begin

cv:=(a[i]+b[i])/2;

dt:=a[i]*b[i];

writeln(f2,cv:4:2,' ',dt:4:2);

end;

close(f1);

close(f2);

end.

uses crt;

const fi='x.inp'

var f1:text;

a,b:array[1..100]of integer;

i,n:integer;

begin

assign(f1,fi); reset(f1);

n:=0;

while not eof(f1) do 

begin

n:=n+1;

readln(f1,a[n],b[n]);

end;

for i:=1 to n do 

  begin

writeln('Chu vi dong ',i,' la: ',(a[i]+b[i])*2);

writeln('Dien tich dong ',i,' la: ',a[i]*b[i]);

end;

close(f1);

readln;

end.

const fi='hcn.inp'     

fo='hcn.out'

var f1,f2:text;   

a,b:array[1..100]of integer;   

i,j,n:integer;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

n:=0;

while not eof(f1) do 

begin     

inc(n);     

readln(f1,a[n],b[n]); 

end;

for i:=1 to n do 

writeln(f2,2*(a[i]+b[i]),' ',a[i]*b[i]);

close(f1);

close(f2);

end.

const fi='hcn.inp'     

fo='hcn.out'

var f1,f2:text;   

a,b:array[1..100]of integer;   

i,j,n:integer;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

n:=0;

while not eof(f1) do 

begin     

inc(n);     

readln(f1,a[n],b[n]); 

end;

for i:=1 to n do 

writeln(f2,2*(a[i]+b[i]),' ',a[i]*b[i]);

close(f1);

close(f2);

end.

Câu 1: 

uses crt;

const fi='bai1.inp'

var f1:text;

a,b:real;

begin

clrscr;

assign(f1,fi); reset(f1);

readln(f1,a,b);

writeln(a*b:4:2);

close(f1);

readln;

end.

Câu 2: 

const fi='bai2.inp'

fo='bai2.out'

var f1,f2:text;

a,b:real;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

readln(f1,a,b);

writeln(f2,a*b:4:2);

close(f1);

close(f2);

end.

Câu 3: 

const fi='bai3.inp'

fo='bai3.out'

var f1,f2:text;

a,b:array[1..100]of real;

i,n:integer;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

n:=0;

while not eof(f1) do 

  begin

n:=n+1;

readln(f1,a[n],b[n]);

end;

for i:=1 to n do  

  writeln(f2,a[i]*b[i]:4:2);

close(f1);

close(f2);

end.