Find Largest number among 3 numbers using switch case in php

<?php 
	    $a = 11; 
	    $b = 2; 
	    $c = 20; 
	    // Swich allows expression 
	    switch($a>$b AND $b>$c){ 
	        case TRUE: echo "$a is bigger"; 
	                   break; 
	        case FALSE: switch($b>$c){ 
	            case TRUE: echo "$b is bigger"; 
	                       break; 
	            case FALSE: echo "$b is bigger"; 
	                        break; 
	        }     
	    } 
	?>