Answer: The map scale
Explanation: A Map Scale is defined as the ratio of the distance on a map to the distance on the surface the map represents. For example, 1 centimetres on a map represents 10 kilometres on the surface of the Earth. What this means is that for every 1 centimetre you measure on the map, that equates to 10 kilometres on Earth/ real life.
The Congo and Niger rivers have interesting irregular courses, and instead of going just in a certain direction, they circle around big areas. This is due to the shape of the landscape, and also because of the types of rocks in the surrounding areas where these two rivers flow.
The shape of the landscape is crucial in the course of a river, since every river is moving through the lowest parts where there isn't obstacles, so these rivers have followed that pattern and it turned out to give them irregular course. Also, the types of rocks on their way are very important, so these rivers managed to get through the sediment rocks as they are easy to erode, but haven't been able to break through the igneous rocks that are much harder.
In areas where the plates come together, sometimes volcanoes will form. Volcanoes can also form in the middle of a plate, where magma rises upward until it erupts on the seafloor, at what is called a “hot spot.” The Hawaiian Islands were formed by such a hot spot occurring in the middle of the Pacific Plate.
Narrow ridges, stream channels, drainage
