1. All longitudes are counted in the direction from the initial meridian to the meridian of 180 °
2. Points located to the west of the initial meridian have a western longitude, which is indicated as follows: XX ° C. d
3. If the points are located east of the initial meridian, then their geographical longitude is considered eastern and is designated as follows: XX ° c. d
4. The initial meridian has a longitude of 0 ° d., And the opposite meridian and lying with it in the same plane has a longitude of 180 ° d
5. The semicircle of any meridian consists of points. Their geographical longitude by value can not be less than 0 ° and more than 180 °
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.