notam cu x segmentul AB, si cu y segmentul CD
y=x-6 si [tex] \frac{1}{4}x= \frac{1}{2}y [/tex]
[tex] \frac{1}{4}x= \frac{1}{2}(x-6) [/tex]
[tex] \frac{1}{4}x= \frac{1}{2}x-3 [/tex]
(1/2 amplificam cu 2, 3 amplificam cu 4)
[tex] \frac{1}{4}x= \frac{2}{4}x- \frac{12}{4} [/tex]
x=2x-12
12=2x-x
12=x
AB=12
CD=12-6=6
