d1mka21,
это вот как-то так
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script>
$(function() {
var a = $(".lenght"),
c = $(".vehicle");
a.each(function(a, b) {
$(b).click(function() {
c.hide().eq(a).show()
});
b.checked && b.click()
})
});
</script>
</head>
<body>
<input type="radio" class="lenght" name="length" checked="checked">
<input type="radio" class="lenght" name="length">
<input type="radio" class="lenght" name="length">
<div class="vehicle">1</div>
<div class="vehicle">2</div>
<div class="vehicle">3</div>
</body>
</html>