The shadow clock is one of the earliest ways of measuring time. It features a figure that is placed upright. When the sun shines on this clock, it casts a shadow of the figure. As the sun rises and sets in the sky, the light hits the clock in different ways. This makes the shadow appear at different angles. This tells what time of the day it is.
Ancient Egyptians used obelisks to measure time. These are a tall, narrow form of the shadow clock. The obelisk was then followed by the sundial. Both the obelisk and the sundial allowed the Egyptians to tell time.
Which example from the text supports the idea that an obelisk is a large stone pillar set up as a monument?
a “Both the obelisk and the sundial allowed the Egyptians to tell time.”
b “The shadow clock is one of the earliest ways of measuring time.”
c “Ancient Egyptians used obelisks to measure time.”
d None of the above