Skew&round
HTML
<div class="wrapper">
<div class="red"></div>
<div class="white"></div>
</div>CSS
.wrapper{
width: 600px;
overflow: hidden;
}
.red{
width: 600px;
height: 200px;
background-color: red;
}
.white{
width: 700px;
height: 200px;
background-color: #fff;
border-radius:20px;
transform:skewX(-20deg);
margin-top:-100px;
}