Building up a triangular lattice

The triangular lattice is sometimes called hexagonal lattice, which may cause some confusion. It can be viewed as a skewed rectangular lattice. It surface density is
- Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \rho\sigma^2=\frac{2}{\sqrt{3}},}
where Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \sigma} is the distance between nodes of the lattice. The dual of this lattice is the honeycomb lattice.