Php Code for Circle

<?php 

    $p=3.14;
    $r=3;
    $d=6;
    $theta=30;
    //Area of Circle
    $Area= $p*pow($r,2); 
    echo "\nArea of Circle is : ".$Area;
    //Diameter of Circle
    $Diameter= 2*$r;
    echo "\nDiameter of Circle is : ".$Diameter;
    //Circumference of Circle
    $Circumference=$p*$d;
    echo "\nCircumference of Circle is : ".$Circumference;
    //Area of Sector
    $Area_Sector= $p*pow($r,2)*(float)$theta/360;
    echo "\nArea of Sector is : ".$Area_Sector;

?>