Property:
lineJoin:

Canvas:
your browser does not support the canvas tag
Code:
var c=document.getElementById('myCanvas');
var ctx=c.getContext('2d');
ctx.lineWidth=10;
ctx.lineJoin='bevel';
ctx.moveTo(20,20);
ctx.lineTo(100,50);
ctx.lineTo(20,100);
ctx.stroke();
Click the property values above to see the result
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