How an Engineer lays out pleats

[unixken]

Steve, tricks like this are used all the time in lots of industries. Years ago I was an advertising design and layout artist. Here's a simple example of one such trick I would use.

Your task - divide an 8-inch wide area into 9 equal columns. You can sit there and do the math to determine how many fractions of an inch each column needs to be... or you can lay your ruler across the 8-inch area, at an angle! Position the ruler such that the "0" (zero) mark on the ruler falls along the left edge of the area you are dividing, and change the angle of the ruler until the mark for 9 inches falls on the right-side boundary of the area you are dividing. Place a tick mark at each inch mark along the angled ruler. Then, using your t-square and triangle, draw a vertical line up through each tick mark. Viola! 9 equal columns without doing any math.