<canvas id="Lines" width="100" height="100" style="border:1px solid black;"></canvas>
<script>
"use strict"
const canvas = document.getElementById("Lines");
const ctx = canvas.getContext("2d");
ctx.beginPath();
ctx.moveTo(10,10);
ctx.lineTo(canvas.width-10, canvas.height-10);
ctx.stroke();
</script>