Решение 6 задачи ( самый грамотный способ)

<?php
class Point

{
    public $x;
    public $y;
    function __construct($x, $y)

    {
        $this->x = $x;
        $this->y = $y;
    }
    function distance(Point $point)
    {
        return sqrt(pow($this-> x -  $point-> x,2 )+pow( $this-> y  - $point-> y, 2));
    }
}
class Trapezoid

{
    public $AB;
    public $BC;
    public $CD;
    public $DA;
    public $h;
    public $perimetr;
    public $s;
    public function __construct($x1, $y1, $x2, $y2, $x3, $y3, $x4, $y4)
    {
        $A = new Point($x1, $y1);
        $B = new Point($x2, $y2);
        $C = new Point($x3, $y3);
        $D = new Point($x4, $y4);
        $this->AB = $A->distance($B);
        $this->BC = $B->distance($C);
        $this->CD = $C->distance($D);
        $this->DA = $D->distance($A);
        $this->h = sqrt(pow($this->AB,2)-pow(($this->DA - $this->BC )/2,2));
    }
    function isEquilateral() : bool
    {
        return $this->AB == $this->CD;
    }
    function getSquare()
    {
        $this->s = ($this->BC+$this->DA) / 2 * $this->h;
        return $this->s;
    }
    function getPerimeter()
    {
        $this->perimetr = $this->AB + $this->BC + $this->CD + $this->DA;
        return $this->perimetr;
    }
}
$n = 4;
$sumSquare = 0;
$averSquare = 0;
for ($i = 0; $i < $n; $i++)
{
$trapecia[$i] = new Trapezoid(rand(5, 10), rand(5, 10), rand(5, 10), rand(5, 10), rand(5, 10), rand(5, 10), rand(5, 10), rand(5, 10));
    echo "Perimeter" .$i . "trapeziod : " . $trapecia[$i]->getPerimeter() . "\n";
    echo "Square" .$i . "trapeziod : " . $trapecia[$i]->getSquare() . "\n";
    if ($trapecia[$i]->isEquilateral())
    {
        echo "trapezoid" . $i . "is equilateral \n";
    }
    else {
        echo "trapezoid" . $i . "is UNequilateral \n";
    }
    $sumSquare += $trapecia[$i]->getSquare();
}
$averSquare = $sumSquare / $n;
$counter = 0;
for ($i = 0 ; $i < $n; $i++)
{
    if($trapecia[$i]->getSquare() > $averSquare)
    {
        $counter++;
    }
}
echo "Average square: " . $averSquare . "\n";
echo "Quantity of trapezoid which square more then Average square: " . $counter . "\n";