Rectangle/cone with css only

Question

Could it be like a rectangle/cone just using css? As in the image below:

I need to use as background of a div or button, but it has to be in this format.

Answer 1

.trapezio { 
  border-top: 50px solid blue; 
  border-left: 25px solid transparent; 
  border-right: 25px solid transparent; 
  height: 0; 
  width: 50px; 
}

<div class="trapezio"></div>

Here’s an excellent reference on how to draw shapes using only CSS