如何在页面上实现一个圆形的可点击区域

可以css，html map标签，js
<!DOCTYPE html>
<head>

</head>
<body>
    
    <div class="disc" onclick="handler()">点击区域</div>
    <img src="D:images159628.jpg" width="206" height="206" border="0" usemap="#Map" />  
    <map name="Map" id="Map">  
     <area shape="circle" coords="100,100,50" href="https://www.baidu.com" target="_blank" />  
    </map>  
   
<script type="text/javascript">
      document.onclick = function(e){
            var r = 50;  //圆的半径
            var x1 = 500,  y1 = 500;  
            var x2 = e.clientX,
                y2 = e.clientY;
            var len=Math.abs(Math.sqrt(Math.pow(x2-x1,2)+Math.pow(y2-y1,2)));  
            if(len<=50){
                handler()
            }
        },

        function handler(){
            debugger
            alert('11')
        }
</script>
</body>
</html>

<style>  
    .disc{  
        100px;  
        height:100px;  
        background-color:dimgray;  
        border-radius: 50%;  
        cursor: pointer;  
        position: absolute;  
        left:50px;  
        top:50px;    
        line-height: 100px;  
        text-align: center;  
        color: white;  
    }  
   </style>