A
a1
X
5) Rotate the laser 90° counterclockwise so that intersection
point stays on c1 point, and the front laser beam passes
through the marks a1 and b1 on the walls A and B
respectively.
6) Mark as c3 the center of the side vertical beam on wall C,
at the same height as point c2. (see figure 8 ).
22
C
X
c2
5 m
c1
X
2.5m
Figure 7
b1
B
X
2.5m