Then BE=y-x
Through the similar (y-x)/x=x/y
y & ampsup2-x & amp; sup2-xy=0
Both sides of the equation are obtained at x & x & sup 2.
(y/x)& amp; sup2-y/x- 1=0
Y/x= (radical number 5+ 1)/2
In fact, it is x:y= golden ratio.