By default SharePoint Classic has vertical radio buttons. Sometime we are getting requirement to make it horizontal. There many ways to do that, one of them you can inject jQuery using content editor webpart on the new and edit form.
For example our default OOTB form as below :

Here is piece of code which you need to add on content editor, it will automatically make all radio buttons of the page to horizontal.

<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script>
    $( document ).ready(function() {
        $(".ms-formtable .ms-RadioText:eq(0)")
        $fields = $('.ms-formbody table');
        $.each($fields, function (i, e) {
                var getRadio = $(e).find('.ms-RadioText:gt(0)');
                $(e).find('.ms-RadioText:eq(0)').append(getRadio);
        }); 
    });
</script>

Once you add your output will be like below :