# What is the greek symbol that represents the ratio of the length and with in a rectangle.

I understand that there is pi, but I was provoked by a question that asked this, "I have a rectangle and if I cut a square off of it it produces the same type of rectangle. I know that the width is 1 meter but what is the length?" Please help me out and tell me the symbol and what it represents.

It's called the golden number/ratio and is represented by the Greek letter phi :$$\phi = \frac{1+\sqrt{5}}{2}$$.
• Some call it $\tau$. – André Nicolas Apr 24 '14 at 0:46