draw a filled Isosceles Triangle
<?php
$width =  601;
$height = 601;
$max_x = $width  - 1;
$max_y = $height - 1;
$mid_y = $max_y / 2;
$mid_x = $max_x / 2;
$fillcolor = '#F00F00';
try {
        $lo_img = new Imagick();
        $lo_img->newImage( $width, $height, new ImagickPixel('transparent'));
        
        $draw = new ImagickDraw();
        
        $draw->setFillColor($fillcolor);
        $draw->setStrokeWidth( 1 );
        
        
                            $co_ords = array( array( 'x' => $mid_x, 'y' => 0 ),array('x'=>0,'y'=>$max_y)
                ,array( 'x' => 0, 'y' => $max_y ),array('x'=>$max_x,'y'=>$max_y)
                 ,array( 'x' => $mid_x, 'y' => 0 ),array('x'=>$max_x,'y'=>$max_y)
                );
        
        
        
        $draw->polyline($co_ords);
        $lo_img->drawImage( $draw );
        
        $lo_img->setImageFormat( "png" );
        
        
        header( "Content-Type: image/png" );
        echo $lo_img;
        
        $lo_img->destroy();
        $draw->destroy();
        exit;
        
    } catch (Exception $ex) {
        print_r($ex);
        return;
    }
?>