Sand, silt, clay
Soils can vary and be like loamy sand, sandy clay, silty clay, etc too
Your not showing us the map so we can not help
In the age of exploration.... Prince Henry showed the Portuguese how to navigate by studying the sun and stars until later on, he showed them the compass navigation as the only technology advance which made possible for them.
A rational number can be in the form of a fraction, integer, whole number..
In this case, the square root of 36 is 6. For the other answer choices, you'll get an irrational number.
Therefore, the answer is square root of 36.