First, the classification of Tower:
Divided by end-use: a straight-line tower (Z), the corner tower (J), a straight line corner tower (ZJ), transposition tower (H), Terminal Tower (D), branch of Tower (F), across the tower (K) and so on. Divided by the structure: glass-type (B), triangular (J), dry type (G), the font (S), Bridge-type (Q), wishbone-type (C), door-type (Me) , Harpoon-type (Yu), drum-type (Gu), V-shaped (V), is an umbrella (Sz), inverted umbrella (Sd), Tin-shaped (T), Selenastrum type (Y), Wang word type (W) and so on. Way into legislation by the group: cable type (L) and self-standing (not expressed). Divided by the voltage level: 35,110,220,330,500,750 (kV) and so on. Divided by the line loop: double-loop (S), single loop (this does not mean that).
Second, and related to the concept of angle: