Bagaimana cara mengirim data lewat Ajax yang benar?

Saya kan mau mengirim data dari select dan inputan.. select berupa karakter * atau # sedangkan inputan berupa angka.. Tapi kenapa lelirimnya undefined ya?

File satu :

 <!-- Prompt IE 6 users to install Chrome Frame. Remove this if you want to support IE 6.
	 chromium.org/developers/how-tos/chrome-frame-getting-started -->

<script defer src="//ajax.googleapis.com/ajax/libs/chrome-frame/1.0.3/CFInstall.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.0/jquery-ui.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<label for="">Pilih Bentuk Segitiga : </label>

<label class="select">
<select name="bintang" id="bintang">
	<option value="#">Pager (#)</option>
	<option value="*">Bintang (*)</option>
</select>

</label>

<h1><b>Input Segitiga</b></h1>
<input type="text" name="Segitiga" id="Segitiga">
	<span class="ribbon-button-alignment ">
	<a href="javascript:void(0);" class="btn btn-default" onclick="Segitigaaa();" id="Segitigaaa" name="cari"><i class="fa fa-search"></i> Hasil</a>
	</span>

<div id="hasil"><div>

<script type="text/javascript">


$(document).ready(function(){
		$('#bintang').select({width:'400px'});
	});

function Segitigaaa(){
	var segitiga = $('bintang').val
	var segitiga2 = $('Segitiga').val
	$.ajax({
	  url: 'hasil.php',
	  type: 'POST',
	  dataType: 'html',
	  data: {'segitiga':segitiga,'segitiga2':segitiga2},
	  success: function(msg) {
	    // alert(segitiga);
	    $('#hasil').html(msg);
	  },
	  error: function(msg) {
	    alert('msg');
	  }
	});

}

</script>

Hasil.php :

 <?php

$Segitiga1 = $_POST['segitiga'];
$Segitiga2 = $_POST['segitiga2'];

for ($a=0; $a < $Segitiga2; $a++) {
 for ($b=$Segitiga2; $b > $a; $b--) {

 	echo "$Segitiga1";

 }
 echo "</br>";
}
?>

Hasil yg diinginkan bentuk segitiga muncul dibawah input