A wire is to be stretched from the top of a building which is 10 meters tall to the second building which is 25 meters tall the buildings are 12 meters apart How long is the wire?

First of all, only if the wire is stretched between the 2 buildings roof edges facing each other, can this question be answered using the information given. (If the wire is stretched between the middles of the roofs, the information given is not enough, in case if we want to give a precise answer, we'd need to know how wide each roof is.) So, anyways, let's presume that the wire is stretched between the roof edges facing each other. The solution is easy if you know the Pythagorean theorem. Imagine a right triangle formed by the distance between the buildings (12 meters), the difference in heights (25-10=15 meters) and the length of the wire. The length of the wire is the hypotenuse, so the formula to calculate its length is a square root of (12 squared + 15 squared) = square root from (144+225) = square root from 369 which is approximately 19.209 meters.