ý 1:

program ct;

uses crt;

var a,b,cv,dt:integer;

begin

clrscr;

write('nhap chieu dai=');readln(a);

write('nhap chieu rong=');readln(b);

cv:=(a+b)*2;

dt:=a*b;

writeln('chu vi hinh chu nhat la',cv);

writeln('dien tich hinh chu nhat la',dt);

readln

end.

Ý 2:

program ct;

uses crt;

var a,cv,dt:integer;

begin

clrscr;

write('nhap canh='); readln(a);

cv:=a*4;

dt:=a*a;

writeln('chu vi hinh vuong la',cv);

writeln('dien tich hinh vuong la',dt);

readln

end.

Ý 3:

program ct;

uses crt;

const pi=3.14;

var cv,dt,r:real;

begin

clrscr;

write('nhap ban kinh='); readln(r);

cv:=2*r*pi;

dt:=sqr(r)*pi;

writeln('chu vi hinh tron la=',cv:4:2);

writeln('dien tich hinh tron la=',dt:4:2);

readln

end.

1.

program ct_btpt;

uses crt;

  var a, b, S, C: real;

begin

  clrscr;

  write('Nhap a = '); readln(a);

  write('Nhap b = '); readln(b);

  S:=a*b;

  C:=(a+b)*2;

  writeln('Dien tich hcn = ', S:2:1);

  writeln('Chu vi hcn = ', C:2:1);

  readln

end.

2.

program ct_btpt;

uses crt;

  var a, S, C: real;

begin

  clrscr;

  write('Nhap a = '); readln(a);

  S:=a*a;

  C:=a*4;

  writeln('Dien tich hv = ', S:2:1);

  writeln('Chu vi hv = ', C:2:1);

  readln

end.

3. 

program ct_btpt;

uses crt;

  var r, S, C: real;

begin

  clrscr;

  write('Nhap r = '); readln(r);

  S:=r*r*pi;

  C:=2*r*pi;

  writeln('Dien tich htron = ', S:2:1);

  writeln('Chu vi htron = ', C:2:1);

  readln

end.