Full width image with fixed height

If you want to have same ratio you should create a container and hide a part of the image.

.container{
  width:100%;
  height:60px;
  overflow:hidden;
}
.img {
  width:100%;
}
<div class="container">
  <img src="http://placehold.it/100x100" class="img" alt="Our Location" /> 
</div>

   

Set the image's width to 100%, and the image's height will adjust itself:

<img style="width:100%;" id="image" src="...">

If you have a custom CSS, then:

HTML:

<img id="image" src="...">

CSS:

#image
{
    width: 100%;
}

Also, you could do File -> View Source next time, or maybe Google.