Fr.: nombre d'or
If a line segment is divided into a larger subsegment (a) and a smaller subsegment (b), when the larger subsegment is related to the smaller exactly as the whole segment is related to the larger segment, i.e. a/b = (a + b)/a. The golden ratio, a/b is usually represented by the Greek letter φ. It is also known as the divine ratio, the golden mean, the → golden number, and the golden section. Its numerical value, given by the positive solution of the equation φ2 - φ - 1 = 0, is approximately 1.618033989. The golden ratio is closely related to the → Fibonacci sequence.