Hình hộp chữ nhật: 

Program BTH;
Uses Crt;
var a,b,c,d:longint;
procedure BTH;
Begin
d:=a*b*c;
end;
Begin
clrscr;
Write('Nhap chieu dai: ');readln(a);
Write('Nhap chieu rong: ');readln(b);
Write('Nhap chieu cao: ');readln(c);
BTH;
Write('The tich hinh hop chu nhat la: ',d);
readln;
End.

Chu vi hình tròn:

Program BTH;
uses crt;
var a:longint;
b:real;
procedure BTH;
begin
b:=a*a*pi;
end;
Begin
Clrscr;
Write('Nhap ban kinh: ');readln(a);
BTH;
Write('Chu vi hinh tron la: ',b:4:2);
readln;
End.

Tính hình hộp

program kha_banh;

uses crt;

var a,b,d,k: real;

begin

writeln('nhap cac canh a,b,c : ');    readln(a,b,c);

k:=a*b*c;

writeln('dien tich hinh hop la: ',k);

readln;

end.

.

.

.

tính chu vi hình tronf

program from_kha_banh_with_love;

uses crt;

var r,a : real;

begin

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

a=*r*3,14;

writeln('chu vi hinh tron la: ',a);

readln;

end.