Найти длину и основание высоты треугольника, опущенной из вершины А на сторону ВС

program triangle;
uses Crt;
var x1, x2, x3, y1, y2, y3 : integer;
S, AB, BC, AC, h : real;
begin
     writeln('Vvedite koordinati A'); readln(x1, y1);
     writeln('Vvedite koordinati B'); readln(x2, y2);
     writeln('Vvedite koordinati C'); readln(x3, y3);
AB := sqrt(sqr(x2-x1)+sqr(y2-y1));
BC := sqrt(sqr(x3-x2)+sqr(y3-y2));
AC := sqrt(sqr(x1-x3)+sqr(y1-y3));
if (AB<BC+AC)and(BC<AB+AC)and(AC<AB+BC) then
 begin
  S := 1/2*abs((x2-x1)*(y3-y1)-(x3-x1)*(y2-y1));
  write('S = ', S);
 end else writeln('Treygolnik ne syshestvyet. Zadayte drygie koordinati');
 end

program triangle;
uses Crt;
var x1, x2, x3, y1, y2, y3 : integer;
S, AB, BC, AC, h : real;
begin
ClrScr;
writeln('Vvedite koordinati A (x,y)');
readln(x1, y1);
writeln('Vvedite koordinati B (x,y)');
readln(x2, y2);
writeln('Vvedite koordinati C (x,y)');
readln(x3, y3);
AB := sqrt(sqr(x2-x1)+sqr(y2-y1));
BC := sqrt(sqr(x3-x2)+sqr(y3-y2));
AC := sqrt(sqr(x1-x3)+sqr(y1-y3));
if (AB<BC+AC)and(BC<AB+AC)and(AC<AB+BC) then
begin
S := 1/2*abs((x2-x1)*(y3-y1)-(x3-x1)*(y2-y1));
write('S = ', S);
end else writeln('Treygolnik ne syshestvyet. Zadayte drygie koordinati');
end.