Meaning of perfect numbers. A perfect number: a number is perfect when the sum of its divisors (except the number itself) equals the given number. Theorem connecting perfect and prime numbers. 6 : The divisors of 6 are 1,2,3 & 6.
Â­A watershed is an area of land that feeds all the water running under it and draining off of it into a body of water. It combines with other watersheds to form a network of rivers and streams that progressively drain into larger water areas. Topography determines where and how water flows.Ridge tops surrounding a body of water determine the boundary of a watershed. Imagine turning an open umbrella upside down in the rain.he umbrella is like a watershed; it collects everything that falls into it. Waterways within the watershed all feed into that main body of water, which could be a river, lake, or stream. The beginnings of a water source are called headwaters.
A watershed is the area of land that drains into a body of water such as a river, lake, stream or bay. It is separated from other systems by high points in the area such as hills or slopes.It includes not only the waterway itself but also the entire land area that drains to it.ow the land in a watershed is used by people, whether it is farms, houses or shopping centers, has a direct impact on the water quality of the watershed. When it rains, stormwater carries with it the effects of human activities as it drains off the land into the local waterway.