Bài 1: 

Program bai1;

Uses crt;

Var a,b,cv,dt:real;

Begin

Clrscr;

Write('Nhap chieu dai va chieu rong:');

Readln(a,b);

If (a>0 and b>0) then 

            begin

            cv:=(a+b)*2;

            dt:=a*b;

            end

Else writeln('Hay nhap canh co gia trị lon hon 0');

Writeln('Chu vi=',cv);

Writeln('Dien tich=',dt);

Readln

End.

Bài 2:

Program bai2;

Uses crt;

Var t,v,tb:real;

Begin

Clrscr;

Write('Diem toan:'); Readln(t);

Write('Diem van:'); Readln(v);

tb:=(t+v)/2;

If (tb>=12 and (t>2 and v>2)) then Writeln('DAU')

                                                 Else Writeln('ROT');

Readln

End.

Bài 1: 
Program bai1;
Uses crt;
Var a,b,cv,dt:real;
Begin
Clrscr;
Write('Nhap chieu dai va chieu rong:')
Readln(a,b);
If (a>0 and b>0) then 
 begin
cv:=(a+b)*2;
 dt:=a*b;
end

Else writeln('Hay nhap canh co gia trị lon hon 0');
Writeln('Chu vi=',cv);
Writeln('Dien tich=',dt);
Readln
End.

Bài 2:

Program bai2;
Uses crt;
Var t,v,tb:real;
Begin
Clrscr;
Write('Diem toan:'); Readln(t);
Write('Diem van:'); Readln(v);
tb:=(t+v)/2;
If (tb>=12 and (t>2 and v>2)) then Writeln('DAU')
 Else Writeln('ROT');
Readln
End.