I have bootstrap framework page, which having two images.

**1st image :** This image has two classes : col-sm-12 and img-rounded .

**2nd image :** This image has only one class : img-rounded.

The problem is , for the first image, the image having no border radius. But if I remove col-sm-12 from the tag , then this border-radius is clearly visible. What is wrong in these two case ?

Why for 1st case, border-radius not showing ?

**[Fiddle here](https://plnkr.co/edit/re581rwI3VKBl7LG57nD?p=preview)**

```
<div class="row" style="background-color:red;">
  <img class="col-sm-4 img-rounded" 
  src="http://images.indianexpress.com/2014/11/doordarshan422.jpg" >
</div>
<br>
<div class="row" style="background-color:red;">
  <img class="img-rounded" 
  src="http://images.indianexpress.com/2014/11/doordarshan422.jpg" >
</div>

```