oop1.php

<?php
header('Content-Type: text/html; charset=utf-8');
class Cars{
    public $mark;// марка
    public $type; // тип
    public $tonnage; // тонаж
}
class  Truck extends Cars {
    public function __construct(){
        echo $this->mark = "MAN ";
        echo $this->type = "Грузовик ";
        echo $this->tonnage = "20 тон";
    }
}
class Bus extends Cars{
    public function GetMark()
    {
        echo $this->mark = "RENO";
        echo $this->type = " Автобус " ;
        echo $this->tonnage = "50 мест";
    }
}
$truck = new Truck();
echo "<br>";
$bus = new Bus();
$bus->GetMark();