Why would British colonists of the 19th century promote the idea that Great Zimbabwe was built by another culture--not Africans? How has this idea been corrected?

To find the distance between the two spots, make use of the Pythagorean Theorem. This states that the sum of the square of its two legs is equal to the sum of the hypotenuse. From the given, the unknown is the hypotenuse and the measure of its legs are the total horizontal and vertical distances. 
                                   h² = (L1)² + (L2)²
Substituting,
                              h² = (2 + 5)² + (5 + 5)²
The value of h (the distance between two spots) is approximately 12.2 miles.