- Draw a rectangle.
- Determine a larger length that divides easily into how many equal spaces you want. (For example, if four equal spaces are required, 10 inches, 12 inches, 16 inches, etc. are good choices.)
- Angle the ruler so that zero and the number chosen, in this case 10 inches, are on the , outside edges of the rectangle. (You may need to extend the vertical lines of the rectangle.)
- Mark the divisions along the ruler and square them vertically. If four divisions are required and 10 inches is chosen, then mark every 2.5 inches on the ruler.
a line/plane straight up and down, vertically level (plumb)