What empire 500 years ago had no real concept of money? what was the unit of value in this empire?

In 1915 the german geologist and meteorologist alfred wegener first proposed the theory of continental drift, which states that parts of the earth's crust slowly drift atop a liquid core. the fossil record supports and gives credibility to the theories of continental drift and plate tectonics.

Equilateral triangle pbj is inscribed in a circle as shown. determine the measure of arc pjb.

Advantages and disadvantages of mitigation and adaptation