Let's start from a simple pattern drawing. Piece 1 is the front leg pattern, piece 2 is the back leg pattern.
If you want to shorten of lengthen the pattern, do that first, then follow the steps below:
1- Measure the hem on the front and back pattern pieces, A and B on the image below.
2- Calculate X=A+B
If C+8 is equal to or greater than D, then Y=C+8.
If C+8 is less than D, then Y=D.
5- Now we need to reduce X to Y and do this proportionally, so next comes a bit of math so concentrate! 😜
6- New front hem length E=A×Y÷X, New back hem length F=Y-E.
7- Mark a distance (A-E)÷2 from each side of the front leg pattern.
8- Likewise mark a distance (B-F)÷2 from each side of the back leg pattern.
10- Draw a straight line from the marks made in steps 7 & 8 to the knee marks.
And leave me a comment below if you have any comments or questions 😊