Rectangle in which the ratio of the measure

*a*of the largest side to the measure*b*of the smallest side is the same as between the half-perimeter (*a*+*b*) and the measure a of the large side.Consider this rectangle:

Therefore: \(\dfrac{a}{b}\) = \(\dfrac{a+b}{a}\)

- The value of the golden ratio is about 1.618 and we write: \(\dfrac{a}{b}\) ≈ 1.618.
- A golden rectangle is a rectangle in which the adjacent sides are in the ratio \(\dfrac{\sqrt{5}+1}{2}\).