return $this->lado * $this->lado; } public function calcPerim() { return 4 * $this->lado; } } class Retangulo extends Quadrilatero { protected $lado2; public function __construct($l1, $l2) { parent::__construct($l1); $this->lado2 = $l2; } public function calcArea() { return $this->lado * $this->lado2; } public function calcPerim() { return 2 * $this->lado + 2 * $this->lado2; } } $g = new Quadrado(15); echo $g->calcArea(); echo $g->calcPerim(); echo "<br>"; $c = new Retangulo(15, 10); echo $c->calcArea(); echo $c->calcPerim();