How to make the button Incline?

An alternative would be to use the pseudo elements :before and :after combined with border and position you can add these two inclined "corners", ie the effect is "simulated", eg:

.exemplo {
  color: #fff;
  position: relative;/*faz os elementos pseudos acompanharem o elemento com a classe*/
  display: inline-block;
  background-color: #CC0000;
  line-height: 20px; /*Centraliza o texto*/
  height: 20px;
  padding:0 10px;
  margin: 0 10px;
}

.exemplo:before, .exemplo:after {
  content: "";
  width: 0px;
  height: 0px;
  top: 0px;
  position: absolute;
}

.exemplo:before {
  border-top: 20px solid transparent;
  border-right: 5px solid #CC0000;
  left: -5px;
}

.exemplo:after {
  border-bottom: 20px solid transparent;
  border-left: 5px solid #CC0000;
  right: -5px;
}

<div class="exemplo">test</div> <div class="exemplo">test</div>

For corners by height, change the border-width from 20px to the desired height at:

.exemplo:before {
  border-top: 20px solid transparent;

and

.exemplo:after {
  border-bottom: 20px solid transparent;

To adjust the slope you must change the border-right and left of .exemplo:before and change border-left and right .exemplo:after %

You can use CSS transform with skew like this:

#inclinada {
    width: 100px;
    height: 20px;
    -webkit-transform: skew(-20deg);
       -moz-transform: skew(-20deg);
         -o-transform: skew(-20deg);
            transform: skew(-20deg);
    background: red;
    cursor: pointer;
    margin-left: 10px;
    padding: 10px;
}

jsFiddle: link

In my example I used margin and padding , and other properties, but this is optional. The important thing is transform: skew(-20deg); and its variants for different browsers.

Change the degrees of inclination to fit what you need.

For the text not to be inclined too, you can do this ( link ) as @bfavaretto mentioned or so ( link ) as @mgibsonbr mentioned