TOOLCRAFT LDM 80T Mode D'emploi page 62

Keep a right angle when measuring the third distance.
3. The product will automatically calculate the distance between point 1
and point 2 and display the reading in the bottom line.
With three reference points (partial section)
1. Press the indirect measurement button (G) three times. The indicator
for indirect measurement with three reference points (partial section)
appears left in the display.
2. Now measure the three necessary lengths. For the correct order,
see the following illustration or follow the blinking segments of the
indicator for indirect measurement with three reference points.
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