[MX V8i] Volume calculating

Hello,

I design pavement  for the first time via input files and being very delighted :) I have a question about cross section strings and calculating the cross section areas based on these strings which are needed in volume calculating. Is it necessary to "vertical closing" areas at the edges? Are these cases identical from point of view of calculating volumes between "red" and "blue" sections? Do I need to design this almost vertical "wings" at the edges of horizontal "red" section?

Best regards
Aleksander Zamorski