A pool table is a green rectangle, the felt, inside a brown frame, the rails. Four numbers name the edges of the
felt; everything else is measured from them.
```js
const LEFT = 20
const TOP = 40
const RIGHT = 460
const BOTTOM = 280
ctx.fillStyle = '#78350f'
ctx.fillRect(LEFT - 12, TOP - 12, RIGHT - LEFT + 24, BOTTOM - TOP + 24)
ctx.fillStyle = '#15803d'
ctx.fillRect(LEFT, TOP, RIGHT - LEFT, BOTTOM - TOP)
```
What it means
The felt goes from x 20 to 460 and y 40 to 280: 440 × 240 pixels.
The rails are a brown rectangle 12 pixels bigger on every side, drawn first; the felt is drawn over it.
Your turn
Under const ctx = ..., leave an empty line and write the four edges.
In draw, under the background fillRect, write the four lines. Press Run.