Hi Nadi,
It looks like you are using LatLong coordinates for geometry and you specify 800 as the default edgeLength.
You have to work in a consistent coordinate system.
If you want to work in LatLong, then edgeLength must also be in degrees.
In general it is best to work in a cartesian coordinate system like UTM and specify edge lengths as metres and then convert the mesh to LatLong afterwards.
Hope this helps... Martin