how to make move able triangle in canvas js

1        function drawTrianlge(e) {   // add this with event listener...
2            var bx = fe.offsetX;
3            var by = fe.offsetY;
4            var x = e.offsetX;
5            var y = e.offsetY;
6            var takeLineLen = Math.abs((bx + by) - (x + y));
7            context.beginPath();
8            context.moveTo(bx, by);
9            context.lineTo(x, y);
10            context.moveTo(x, y);
11            context.lineTo(takeLineLen - x / 2 , y);
12            context.moveTo(takeLineLen - x / 2 , y);
13            context.lineTo(takeLineLen - y / 2 , by);
14            context.stroke();
15            context.closePath();
16        }

1        function drawTrianlge(e) {     // add eventlistener!!!
2            var bx = fe.offsetX;
3            var by = fe.offsetY;
4            var x = e.offsetX;
5            var y = e.offsetY;
6            context.beginPath();
7            context.moveTo(bx, y);       
8            context.lineTo(x, y);
9            context.lineTo(x, by);
10            context.closePath();
11            context.stroke();            
12        }