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HTML

              
                <canvas id="my-canvas" 
  width="500" 
  height="500" 
  style="border: solid 1px black">
 
</canvas>
              
            
!

CSS

              
                
              
            
!

JS

              
                const ctx = document.getElementById('my-canvas').getContext('2d');
drawPolygonPath(6, 150, 250, 250, ctx);//画路径
ctx.stroke();//描边
function drawPolygonPath(sideNum, radius, originX, originY, ctx){
  ctx.beginPath();
  const unitAngle = Math.PI * 2 / sideNum; //计算单元角度
  let angle = 0; //初始角度
  let xLength, yLength;
  // ctx.moveTo(originX, originY);
  for(let i = 0; i < sideNum; i++){ //遍历计算点,并lineTo()绘制路径
    xLength = radius * Math.cos(angle);
    yLength = radius * Math.sin(angle);
    // console.log('xLength: ' + xLength);
    // console.log('yLength: ' + yLength);
    ctx.lineTo(originX + xLength, originY - yLength);//绘制路径
    angle += unitAngle;
  }
  ctx.closePath();//闭合路径,也可在for循环中多一次循环lineTo()至起点
}

              
            
!
999px

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