, -
<div id="curves" class="width">
<div id="curve1"></div>
</div>
<div id="one">a</div>
#curves div {
margin-top: 100px;
width: 400px;
height: 400px;
border: 5px solid #999;
}
#curves.width div {
border-color: red red transparent transparent;
}
#curve1 {
border-radius: 100% 100% 100% 0;
}
#one {
position: absolute;
left: 300px;
top: 105px;
}
, Fiddle, , , java- script/jquery
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