Final answer:
Early civilizations measured sizes through artistic representations like the proportionate Terra Cotta warriors and the hierarchical scale in Egyptian art. Populations of cities in civilizations such as Sumer and Athens also indicate the scale of these societies, as do monumental structures like pyramids and temples that symbolized power and wealth.
Step-by-step explanation:
Early civilizations compared sizes in a variety of ways, often reflecting their social and political structures. For instance, the Terra Cotta warriors of China were created life-sized to give a realistic representation of an army, exemplifying the importance of proportion in their artwork. In contrast, hierarchical scale was used by the Egyptians, depicting pharaohs as much larger than lesser figures to indicate their greater importance.
In terms of population and city size, early civilizations such as those in Sumer saw numbers ranging from 10,000-20,000, ballooning to approximately 50,000 for larger cities like Uruk. Similarly, Athens during the age of Pericles and Socrates had a population of about 100,000. These population sizes indicate the scale of urban development and the extent of these civilizations.
Rivers like the Nile, Yellow, and Tigris provided the means for early cities to thrive and develop extensive agricultural systems that supported large populations. Monuments and buildings constructed during these times, such as pyramids and temples, became reflections of the power and wealth of the ruling classes, indicating both the scale of these societies' ambitions and their ability to mobilize resources and labor.