Final answer:
Africa is renowned for its high percentage of geometric boundaries separating its states, a legacy of European colonization which created borders often without regard to the continent's ethnic and cultural divisions.
Step-by-step explanation:
The region that has a high percentage of geometric boundaries to separate states is Africa. In contrast to natural physical geographic features such as rivers and mountain ranges, which often serve as boundaries in other parts of the world, Africa's colonial history resulted in many borders that are straight lines or follow lines of latitude and longitude, which are examples of geometric boundaries. These boundaries were established during the period of European colonization without much regard for the ethnic and cultural divisions that existed among the African people.
For example, the boundary between Egypt and Libya is largely a straight line, as is the border between Namibia and Angola. Moreover, the borders within the Sahara Desert are often geometric, as the harsh climate has prevented the development of significant natural features that could serve as boundaries. Because of this colonial legacy, many African nations have borders that reflect these geometric shapes rather than the natural landscape.