The document root directory is /var/www/html and it's defined in /etc/httpd/conf/httpd.conf.
This isn't really the right forum for asking questions about Apache, though. Apache Tomcat isn't the same thing as Apache httpd. It's confusing, since we generally say "Tomcat" for Apache Tomcat, but "Apache" for Apache httpd.
An IDE is no substitute for an Intelligent Developer.