Not that each civilization didn't have their own measurement system, but to build something as massive as Notre Dame or Angkorian, how did the architects convey the proper measurements for both during construction and material gathering?
Much like the current imperial system, the ancient used measurements units based on the human body.
For example, ancient Romans used feet and cubits. Egyptians used similar units, although with different values. This approach was also used in the Middle Ages and, through the imperial system, has survived to date.
To measure length, measuring sticks were often used.
There is evidence that Egyptians used "ceremonial cubits" rods for both religious and measurement purposes. Several Egyptian measurement sticks have been discovered, including the "Amenemope cubit rod", so-called after a Pharaoh of the 21st Dynasty (around 1000 BCE).
Similar rulers were used by the Romans.
The Aztecs used a measurement unit that was called "Tlalcuahuitl". As huitl meant "rod, stick, staff", it is very likely they also used measurement rods, especially because their measurements were pretty accurate, at least in land surveying.
The Bible also mentions measuring sticks, and so does an ancient Sumerian religious text.
Measuring rods were also used in the Middle Ages, although with differences sometimes from town to town.