How to make an algorithm to calculate circumference of circle

Acivilization reaches its high point during its stage. a)birth b)growing pains c)adulthood d)senior

Many blacks moved from the south to northern cities during world war li looking for employment. after the war, a number of them lost their jobs. why did this happen?

Why might the spanish government have approved of the encomienda system? a the system allowed for fair treatment of all under it, leading to a happy and prosperous colony. b the system used natives as slaves which meant the government was able to maximize their profit of exported goods. c the system allowed for mostly profitable trade within the different colonies. d the system was a great example of how to successfully run a colony, making spain a world power.