<div></div>
body{
background-color:rgba(255,165,0,.2);}
div{
background-color:tomato;
width:100px;
height:100px;
position:relative;
top:100px;
left:50%;
transform: rotate(-45deg);}
div:before{
content:"";
width:100px;
height:100px;
border-radius:50%;
background-color:tomato;
position:absolute;
top:-50px;
left:0;}
div:after{
z-index:-1;
content:"";
width:100px;
height:100px;
border-radius:50%;
background:tomato;
position:absolute;
top:0px;
left:50px;}