The golden ratio is a mathematical constant approximately equal to 1.6180339887. It is the ratio between two quantities where the ratio of the whole to the larger part is equal to the ratio of the larger part to the smaller part. The golden ratio is found throughout nature and is considered aesthetically pleasing in architecture and art. It appears in structures like the Parthenon and in works by Leonardo Da Vinci. Fibonacci numbers approach the golden ratio as the numbers increase. While not always precise, the golden ratio approximates proportions found in plants, shells, the human body, and other biological systems.