How long should the "reason for applying", "how did you learn..", etc. short answers be?

I’ve had my essays done for a while, but I just started looking at SMU and am interested in applying. How long should they be? I know it says a max of 40 lines, but I don’t want to make mine so short that it gets looked over for being so brief. Thank you!

Always follow the instructions - so 40 lines or less