how to change jumbotron size

    .jumbotron {
      background: url('http://placekitten.com/800/500') no-repeat center center;
      background-size: cover;
      padding-top: 20%;
      padding-bottom: 20%;
    }

.jumbotron
{   
padding-top: 0px;
padding-bottom:0px;
background-image:url('images/car/car.jpg');
background-size: cover;
height:560px;
 }