STEP 2.2
If your TV wall-mount looks like Fig. B, you
need to measure the H3. H3 means the height
from the down-facing hook of TV bracket to
the top of the wall plate. Then you can locate
the height of the top of the wall plate.
Option A:
H= H0+H1+H2-H3.
Option B:
H=X-Htv/2+H2-H3
Choose the option A or B according to your
needs.
Then mark a horizontal line at the height of H.
After that, you can secure the wall plate on the
wall along with the horizontal line.