Geometry and meaning of road traffic signs

Provisions on the geometry of the draft international "colors and safety signs" standard is: The triangle. Display road traffic signs  is high, irrespective of light conditions, than the other shape attract sb.'s attention. Our country adopts the triangle for the road traffic signs geometry, using inverted triangle in the "parking way" and "slow.". The circular. Circular display a higher degree, vision, also easy to led flashing traffic sign  text, our country will round for prohibition and indicating two marks of geometry. The square. Including rectangular and square, its visibility, for the road traffic signs geometry.