Method II
| Construction of the grid : | ||
| 1. Draw the diagonals to create M (figure 1), draw a line parallel to AB through M (figure 2). Measure the intercepts a and b and divide AB accordingly to create F. Draw a line e through M and F. | ||
| 2. Do correspondingly for AC to create g (figure 3). | ||
| 3. The lines e and g present the base of the grid (figure 4) which can now be completed as shown in figure 5 and 6. |