How does the indirect (also called Triangulation or Pythagorean) method work?
Laser measuring devices use a process called triangulation to calculate indirect measurements. Triangulation involves measuring two sides of a right triangle and mathematically determining the missing (3rd) side using the Pythagorean Theorem the sum of the squares of the two sides (shortest legs) of a right triangle is equal to the square of the hypotenuse (longest side). For example, if you were able to position yourself at the southwest corner of a house (facing north) so that you can see the complete south side of the house (off to your right) and also at a position perfectly in line with the west side of the house, you have created a right triangle. One leg of the right triangle is the distance from you to the southwest corner of the house. The diagonal measurement from you to the southeast corner of the house is the hypotenuse (longest side). The third side (missing leg) is the distance from the southwest corner to the southeast corner of the house. With indirect measurements, the
