<?php
/*
* 这是按形状的抽象类写的一个三角形的计算方式
*
*/
class Triangle extends Shape {
private $bian1;
private $bian2;
private $bian3;
function __construct($arr = array()) {
if(!empty($arr)) {
$this->bian1 = $arr['bian1'];
$this->bian2 = $arr['bian2'];
$this->bian3 = $arr['bian3'];
}
$this->name = "三角形";
}
function area() {
$p = ($this->bian1 + $this->bian2 + $this->bian3)/2;
return sqrt($p*($p-$this->bian1)*($p-$this->bian2)*($p-$this->bian3));
}
function zhou() {
return $this->bian1 + $this->bian2 + $this->bian3;
}
function view() {
$form = '<form action="index.php?action=triangle" method="post">';
$form .= $this->name.'第一个边:<input type="text" name="bian1" value="'.$_POST['bian1'].'" /><br>';
$form .= $this->name.'第二个边:<input type="text" name="bian2" value="'.$_POST['bian2'].'" /><br>';
$form .= $this->name.'第三个边:<input type="text" name="bian3" value="'.$_POST['bian3'].'" /><br>';
$form .= '<input type="submit" name="dosubmit" value="计算"><br>';
$form .='<form>';
echo $form;
}
function yan($arr) {
$bj = true;
if($arr['bian1'] < 0) {
echo "第一个边不能小于0!<br>";
$bj = false;
}
if($arr['bian2'] < 0) {
echo "第二个边不能小于0!<br>";
$bj = false;
}
if($arr['bian3'] < 0) {
echo "第三个边不能小于0!<br>";
$bj = false;
}
if(($arr['bian1']+$arr['bian2'] < $arr['bian3']) || ($arr['bian1'] + $arr['bian3'] < $arr['bian2']) || ($arr['bian2']+$arr['bian3'] < $arr['bian1'])) {
echo "两边之和必须大于第三个边";
$bj = false;
}
return $bj;
}
}
