Warning: Cannot modify header information - headers already sent by | PHP e MySQL II: Cookies, sessões e mais recursos

Utilizando os exemplos da de Cookies e Sessões, ao tentar acessar o arquivo MENU.PHP diretamente digitando pelo browser, ele apresenta a mensagem:

Warning: Cannot modify header information - headers already sent by (output started at /home/espac356/public_html/cabecalho.php:13) in /home/espac356/public_html/logica-usuario.php on line 9

Agradeço a quem puder dar uma ajudinha

/*Arquivo MENU.PHP*/
<?php 
require_once("logica-usuario.php");
require_once("cabecalho.php");
verificaUsuario(); ?>
<style>
  .medio {
    height: 70px;
          }
</style>
<div class="col-xs-14"><hr></div>

<a href="form_usuario.php">
  <button type="button" class="btn btn-primary btn-lg  form-control medio">
    <span class="glyphicon glyphicon-user" aria-hidden="true"></span> Usuários  
  </button></a>
  <br/>
  <br/>  
  <a href="form_morador.php">
  <button type="button" class="btn btn-primary btn-lg  form-control medio">
    <span class="glyphicon glyphicon-home " aria-hidden="true"></span> Moradores  
  </button></a>
  <br/>
  <br/>  
   <a href="form_avisos.php">
  <button type="button" class="btn btn-primary btn-lg  form-control medio">
    <span class="glyphicon glyphicon-volume-up " aria-hidden="true"></span> Avisos  
  </button></a>


<?php require_once("rodape.php");?>

/* Arquivo CABECAOLHO.PHP*/
<html>
<head>
    <title>Teste</title>
    <meta charset = "utf-8"/>
        <link rel="stylesheet" type="text/css" href="css/bootstrap.min.css"/>
        <meta name="viewport" content="width=device-width, initial-scale=1"/>
        <link rel="shortcut icon" href="images/favicon.ico" type="image/x-icon"/>
</head>

<body>
      <div class="container">
    <div class="principal">
    <img class="center-block" src="images/dez_rm_logo.png" class="img-responsive" alt="Teste">

/*Arquivo logica-usuario.php*/
<?php 
session_start();
function usuarioEstaLogado() {
    return isset($_SESSION["usuario_logado"]);
}

function verificaUsuario() {
     if(!usuarioEstaLogado()) {
     header("Location:index.php");
     die();
  }
}

function usuarioLogado() {
  return $_SESSION["usuario_logado"];
}

function logaUsuario($email) {
    $_SESSION["usuario_logado"] = $email;
}

/*Arquivo INDEX.PHP*/
<?php require_once("cabecalho.php");
?>
<h3 class="text-center">Bem-vindo!</h3>
<h4 class="text-center">Por favor, digite seu usuário e senha</h4>
<?php
 if (isset($_GET["login"]) && $_GET["login"]==1) {
  ?>
  <p class="alert-success text-center">Logado com sucesso</p>
<?php }
  if (isset($_GET["login"]) && $_GET["login"]==0) {
    ?>
  <p class="alert-danger text-center">Usuário ou senha inválidos</p>
<?php }
  ?>
<form class="form-horizontal" action="login.php" method="post">
  <div class="form-group">
    <label for="inputEmail3" class="col-sm-2 control-label">E-mail</label>
    <div class="col-sm-10">
      <input type="email" class="form-control" name="email" placeholder="E-mail">
    </div>
  </div>
  <div class="form-group">
    <label for="inputPassword3" class="col-sm-2 control-label">Senha</label>
    <div class="col-sm-10">
      <input type="password" class="form-control" name="senha" placeholder="Senha">
    </div>
  </div>
  <div class="form-group">
    <div class="col-sm-offset-2 col-sm-10">
      <button type="submit" class="btn btn-primary btn-default">Login</button>
    </div>
  </div>
</form>    

<?php require_once ("rodape.php");?>