It is found by dividing a line into two parts so that the longer part divided by the smaller part is also equal to the whole length divided by the longer part.

Golden Ratio is often symbolised by using letter phi.

The value of phi is 1.618 Golden Ratio is also called as a golden mean, golden section or a divine proportion.

Historically, the number can be seen in the architecture of many ancient creations like the great pyramids and the Parthenon.

Please refer above image for the figure and formula to find out the Golden ratio of any rectangular shape body.

The Golden Ratio is an irrational number with never-ending infinite numbers of digits, 1.618033988749895..., which are highly confusing and misleading. It is a linear number and represents only two dimensions of the object.
Drawing It

Here is one way to draw a rectangle with the Golden Ratio:

Draw a square (of size "1")
Place a dot half way along one side
Draw a line from that point to an opposite corner (it will be âˆš5/2 in length)
Turn that line so that it runs along the square's side

Then you can extend the square to be a rectangle with the Golden Ratio.