What fraction of all us residents lived in surburban neighborhoods in the year 2000?

While most people who lived in ancient egypt and the middle east avoided settling in nearby deserts, those regions protected them from their enemies. why do you think this was true?

Based on what you know about the location of the earth in relation to the sun, why is this called the goldilocks zone in other galaxies?

In the diagram below dab and dac are adjacent angles