that third strip (really the 2nd) has to = the width of the first strip, no matter how many sub-strips the first one or the second one is made of. the first strip can be one, two, five nine substrips. that has to equal the second strip, also made of any number. you lay one above the othe, right sidea together, then follow the method. no matter how many substrips there are, from one to 100, it works the same way, as long as the width is the same. when you stack them, they have to be the same width.
they are, indeed, on the bias, as said by rpse marie. thank you,rose marie, for the reminder.