Question about the size of a side piece of cardigan

I posted this on the Starsky knit-a-long, but figured more people would see it here. On the drawing of the different finished pieces showing the dimensions, why is there a line to the left of the side piece that is 3.5 inches from the drawing? I’ve only made pullovers knitted in the round, and haven’t dealt with all these pieces before! Here’s the link to the pattern:

The black lines indicate the size of the piece itself and the blue line indicates the addition of the ribbed collar at the end.

Aha!!! [size=2][/size]I completely forgot I had to make a collar!

[size=3][/size]Thank you so much for clearing that one up for me!