barrons question on polar curve

muneebrocks
Fri, 06 Dec 2013 04:46:00 +0000

http://s23.postimg.org/6xjv0gtbf/Capture.png

I understood the explanation given here

http://s21.postimg.org/m3bo2cg3r/Capture.png
but I dont understand how they got the fact that the length of x and of y was 1?
if x+y=1 shouldnt it be x=.5 and y=.5?