Multiple Inheritance Using Interface in PHP OOP

<?php

interface Shape1
{
    public function area();
}

interface Shape2
{
    public function area();
}

class Rectangle implements Shape1, Shape2
{
    private $width;
    private $height;

    public function __construct($width, $height)
    {
        $this->width = $width;
        $this->height = $height;
    }

    public function area()
    {
        return $this->width * $this->height;
    }

    public function perimeter()
    {
        return ($this->width + $this->height) * 2;
    }
}

$rectangle = new Rectangle(5, 20);
echo 'area: ' . $rectangle->area();
echo '<br>perimeter: ' . $rectangle->perimeter();

?>

Output

area: 100
perimeter: 50