Need help for 3D Trilateration

[testqaibs]

Hi,

I am using Trilateration code (https://github.com/Wayne82/Trilateration) for to calculate location in 3D.
I am using CalculateLocation3d method for to find out the location.

Trilateration worker;
PosAndDistance3dVec beacons;
Pos3d location;

beacons.push_back(PosAndDistance3d(Pos3d(0, 0, 0), 6.09));
beacons.push_back(PosAndDistance3d(Pos3d(4.5, 0, 0), 6.09));
beacons.push_back(PosAndDistance3d(Pos3d(4.5, 9.6, 0), 6.09));
beacons.push_back(PosAndDistance3d(Pos3d(0, 9.6, 0), 6.09));

worker.CalculateLocation3d(beacons, location);

Expected result: (2.25, 4.8, 3) But it gives Z-axis value as 0.
Please help me if I am missing anything.

Thank you,
Pravin