Вычисление периметра трёх прямоугольников, используя функцию

program quadrangle;
 
var a: array [1..4, 1..3] of real;
    p: array [1..3] of real;
    t: real;
    i, j: integer;
 
function perimetr(x, y, z, p: real): real;
begin
  perimetr := x + y + z + p
end;
 
begin
  for j := 1 to 3 do
    begin
      writeln('Enter arms of an quadrangle #', j);
      for i := 1 to 4 do
        begin
          write(i, ': ');
          readln(a[i, j])
        end;
      writeln
    end;
  for j := 1 to 3 do
    begin
      p[j] := perimetr(a[1, j], a[2, j], a[3, j], a[4, j]);
      writeln('Perimeter of quadrangle #', j,' = ', p[j]:10:3)
    end;
  writeln;
  t := p[1];
  i := 1;
  for j := 2 to 3 do if p[j] > t then
    begin
      t := p[j];
      i := j
    end;
  writeln('Maximal perimeter = ', t:10:3, ', quadrangle #', i);
  readln
end.

program rectangle;
 
var a: array ['a'..'b', 1..3] of real;
    p: array [1..3] of real;
    t: real;
    i: char;
    j, k: integer;
 
begin
  for j := 1 to 3 do
    begin
      writeln('Enter arms of an rectangle #', j);
      for i := 'a' to 'b' do
        begin
          write(i, ': ');
          readln(a[i, j])
        end;
      writeln
    end;
  for j := 1 to 3 do
    begin
      p[j] := 2 * (a['a', j] + a['b', j]);
      writeln('Perimeter of rectangle #', j,' = ', p[j]:10:3)
    end;
  writeln;
  t := p[1];
  k := 1;
  for j := 2 to 3 do if p[j] > t then
    begin
      t := p[j];
      k := j
    end;
  writeln('Maximal perimeter = ', t:10:3, ', rectangle #', k);
  readln
end.