<style>
    div#t {
        width: 200px;
        height: 200px;
        border: 20px solid rgba(255,0,0,1);
        border-radius: 100px;
        border-top-right-radius: 0px;
        border-bottom-left-radius: 0px;
        border-left-color: rgba(0,0,255,1);
        background-color: green;
        box-sizing: border-box;
        margin: 20px;
        border-top-width: 10px;
        border-bottom-width: 10px;
        border-left-width: 36px;
        border-right-width: 0px;
    }
</style>
<div id="t"></div>