3841
De Longitudine - Cerlos
Pepernoot
Greetings reader. I am Cerlos, a scholar currently living West of Al'Khazar. In this book I will explain how to calulate distances, using two known distances, which intersect eachother at a straight angle. :: Lets take the example of a triangle, with two straight edges of lengths three and four. We know the length of the third edge is five. You can measure this. But how do we know what the length is when we have different numbers? To explain this, I will have to teach you an old formula, which always give the right length. To understand this I will first have to explain some things first. :: :: Squaring numbers. :: A square of a number is the number of squares that are in an area of a square with both edges of the same length. For example the square of one. If you have a square with two sides length one, the area is one. Next the square of two, if you have a square of sides two in length, the area is four squares. To continue the square of three, which is an area of nine squares. :: :: There is also a way to revert the squaring of a number. The square root. :: The way to know these is remembering the squares of numbers. For example the square root of an area of twenty-five is five, because five squared is twenty-five. :: :: Now we can use these to calculate the distances! :: Let's take our example, the two lengths of three and four. To calculate the diagonal length, we take the squares of both numbers, add them, and take the square root of that number. So that would be nine and sixteen, adding these makes twentyfive. Take the square root of twentyfive, and you have the length, five!