---
title: utils.beamIntersectsLine()
---

The `utils.beamIntersectsLine()` function finds the intersection between an endless
line (beam) and a (limited) line segment. Returns a [Point](/reference/api/point) object for the
intersection, or `false` if the beam doesn't intersect the line.

The first two points in the parameter list form the beam, the last two points form the line.

## Signature

```js
Point | false utils.beamIntersectsLine(
  Point beamA,
  Point beamB,
  Point lineA,
  Point lineB
)
```

## Example

<Example caption="A Utils.beamIntersectsLine() example">

```js
({ Point, points, Path, paths, Snippet, snippets, utils, part }) => {
  points.A = new Point(45, 20)
  points.B = new Point(60, 15)
  points.C = new Point(10, 10)
  points.D = new Point(50, 40)

  paths.AB = new Path().move(points.A).line(points.B).addClass('dotted')
  paths.CD = new Path().move(points.C).line(points.D)

  snippets.x = new Snippet(
    'notch',
    utils.beamIntersectsLine(points.A, points.B, points.C, points.D)
  )

  return part
}
```

</Example>