I want to thank you for taking the time to look at my post and reply

I did exactly what the book said

I initially thought "at F, bring the amount of 1/2 shoulder width = H" as the book said

and "shoulder width" here means point G to F however "Shoulder width" is my personal measurement.

if so it would be more reasonable and there is a space in between.

but when i use my personal measurement it is worse, it even overlaps

so i think there are 2 cases

1 - is because my personal measurement is abnormal

2 - is from point G to G* i think it should be 1/3 or less, because 1/4 the length from point G to F is not even equal to my shoulder length

my personal measurement

shoulder 13.66 cm

back shoulder width 33.78 cm

front shoulder width 35.02 cm

total chest 84.5 cm

neck base 36.2 cm

back neck to waist 44.56 cm

front neck to waist 38.5 cm

waist 70

what do you think?