Adding a new widget area to the left side of the twenty thirteen theme

Hello,

So I am trying to create a real estate website and I want to add a new widget area to the left side of the screen, i have created a child theme and have registered a new widget area using this piece of code in the functions.php.

register_sidebar( array(
		'name'          => __( 'Left Widget Area', 'twentythirteen' ),
		'id'            => 'sidebar-3',
		'description'   => __( 'Appears on left side of page.',   'twentythirteen' ),
		'before_widget' => '<aside id="%1$s" class="widget %2$s">',
		'after_widget'  => '</aside>',
		'before_title'  => '<h3 class="widget-title">',
		'after_title'   => '</h3>',
	) );

I also added this piece of code to a new sidebar.php template.

<?php
/**
 * The sidebar containing the third widget area
 *
 * Displays on posts and pages.
 *
 * If no active widgets are in this sidebar, hide it completely.
 *
 * @package WordPress
 * @subpackage Twenty_Thirteen
 * @since Twenty Thirteen 1.0
 */

if ( is_active_sidebar( 'sidebar-3' ) ) : ?>
	<div id="tertiary" class="sidebar-container" role="complementary">
		<div class="sidebar-inner">
			<div class="widget-area">
				<?php dynamic_sidebar( 'sidebar-3' ); ?>
			</div><!-- .widget-area -->
		</div><!-- .sidebar-inner -->
	</div><!-- #tertiary -->
<?php endif; ?>

However all this does is replace the existing widget areas, so my main and second sidebar disappears in the dashboard. I can’t seem to find where i can position my third widget area.

link to my site :My Website

I have looked at other posts but they don’t show you how they have done it.

link: Forum post

Am i on the right track or is there something I am missing, can someone help me?