<title>Opg. 13 | Triangle</title>

<?php
$i = 9;


    for($row = 0; $row <= 10; $row++)
    {
        for($j = 0; $j <= $i; $j++)
        {
            echo $j;
            if($j < $i)
        {
                echo ",";}}

        echo "<br>";
        $i--;
    }