How to detect if current page is sub page of a certain page?

Hello,

I want to display certain images based on specific page and its sub pages. What I need to do is, set a same image for a page and all its sub pages. Am using is_page() with the page ID, but is there any WordPress way to also have a condition based on sub pages of a certain page.

Am using below code in my header.php

<?php if (is_page(‘114’) or $post->post_parent) { ?>
IMAGE 1
<?php } elseif (is_page(‘115’) or $post->post_parent) { ?>
IMAGE 2
<?php } else { ?>
IMAGE 3
<?php } ?>

$post->post_parent is not working. Is there something like $post->post_parent(‘2’)?