The article under review is devoted to the problem of describing finitely generated biautomatic groups. Let \(\Sigma_0\) be a simplicial complex corresponding to a filling of the Euclidean plane by equilateral triangles. A simplicial complex \(\Delta\) is called a triangular building if it can be represented as the union of a family of subcomplexes \(\Sigma\) (planes) with the following properties: (B0) every plane \(\Sigma\) is isomorphic to \(\Sigma_0\); (B1) every pair of simplices of \(\Delta\) is included in some plane; (B2) for two arbitrary planes \(\Sigma\) and \(\Sigma'\) with a common 2-simplex, there is an isomorphism \(\Sigma\to\Sigma'\) which preserves any point of the intersection \(\Sigma\cap\Sigma'\). For every triangular building \(\Delta\), a type function \(\tau\colon\Delta_0\to\mathbb{Z}/3\) can be defined, where \(\Delta_0\) is the set of vertices of \(\Delta\). The author calls an automorphism \(\varphi\in\Aut(\Delta)\) a type-rotating automorphism if \(\varphi\) induces either an identical action on the set of types \(\mathbb{Z}/3\) or an action without fixed points. The author obtains the following result (Theorem 4): If a group \(G\) acts simply transitively on the vertices of a locally finite triangular building \(\Delta\) by type-rotating automorphisms then \(G\) admits a biautomatic structure. The author presents a geometric class of groups which consists of biautomatic groups.