Earth:
Our planet is the only known habitable place to live in this universe, as there are various regions of different characteristics(i.e dimensions), there are high peaks, as well as deep sea bed inside the oceans (the Mariana trench). So, what shape does the earth poses as a single celestial body in the solar system.In order to find out the question many research workers contributed there time and efforts, and they performed there analyses on the basis of the earth's dimensions.
Explanation:
Dimensions of the Earth:
To know about the length, Mass and the time(M,L,T) in which a physical quantity exists we carry the dimensional analyses of that entity. As for the planet Earth, it does not matter if there are some high peaks or any sort of deep trench inside the oceans. It does not really matter while we measure the roundness and the smoothness and roundness of the planet.As we have the following reasons to conclude:
Smoothness  and roundness of Earth:
We say that earth is a sphere and for a perfect sphere its roundness ratio value must be equal to "1". Now, after analyses of the planet earth from outer space, the researchers or scientists concluded that earth surface is completely smooth, and its a perfect sphere. It does not matter that there are high mountain ranges or even deep trenches inside the oceans.
We can evaluate the results, if we want to derive some mathematical results by using the following formula;
Lets say we take the height of "the K2", which is the second highest mountain on our planet,now:Actual height of "K2", then putting the values in the following formula will give us the results,Actual height of K2/earth diameter= relief diagram height of earth/Diameter of relief diagram.
Earth has no rough edges if we look at its over all structure, it is a completely round in shape, and has a perfect smooth surface overall.
