I want to find out the position (x,y) of a given point, knowing the distance from 3 x,y points.

Below you can view the x,y coordinates and their given distances in **cm**.

    B1x = 795
    B1y = 332
    B1d = 245.735630302
    
    B2x = 795
    B2y = 569
    B2d = 327.946642001
    
    B3x = 516
    B3y = 569
    B3d = 220.635445928

I have had a look at [this question][1], but this is for earth, and I get the error:

`z = math.sqrt(pow(DistA,2) - pow(x,2) - pow(y,2))
ValueError: math domain error`

**FIXED** the above error with `abs` to allow negative numbers but getting the wrong coordinates.

I want my algorithm to calculate in a 2D environment, with the given values above.

Here is the map:

You can see the **green X**, is where I want to locate, from the three given beacons (x,y) locations.

![enter image description here][2]


  [1]: https://gis.stackexchange.com/q/66
  [2]: https://i.sstatic.net/hgEc8.jpg