Very easy gravity is strong from the universe.
Basically add up all the sides... And that's the perimeter don't forget to add your units
The first one, valleys. Rivers had to be built over, no one wanted their farms to be turned into a railroad (or at least those with common sense), and deserts had no water and was really hot during the day and cold at night.
More, more. Because the ocean is more deep and thick and its more colder than shallow warm water
For Earth to make one complete revolution around the Sun takes 365.24 days. This amount of time is the definition of one year.
Effects of Revolution of the Earth: Certain areas are tipped towards, or away from, the sun at different times of the year. This tilting causes the four seasons of the year. The tilting also creates opposite seasons in the Northern and Southern Hemispheres.
