How did environmental factors sometimes lead to disruption along the arabian trade routes

Draught

Explanation:

These were known as the intense trade routes which are a major network of land and sea routes, linking the Mediterranean world with eastern and southern sources of species stretching from North Africa and Arabia. A most important part of this route was the Persian Gulf due to its prominent position Yemen attracted people to settle in fertile crescents. The third-century seemed to be significant for the Arabian traders as the nature of trade completely changed. Drastic climatic conditions disrupted the trade which was brought to a halt by the poor economic conditions. As a fall in the coffee production and decline of ports such as Alexandria led to the decline.

I'm pretty sure there's a geometry rule for   anyways, if the triangle is equilateral, and the circle is circumscribed, the circle is outside of the triangle.  to find the area, you need the radius.  the radius should be a straight line from the center of the triangle to any of it's points.  draw lines from the center of the circle to each of the triangle points.  draw three more lines from the center to the middle of the sides of the triangle.  you should now have six separate 30-60-90 triangles inside of your original triangle. use your 30-60-90 rules to solve for the radius, then the circumference. 

B.a pop up at ion changes in response to a change in the environment.