The method involves generating or determining two sight lines toward two target points (A, B) unspecified in a space, using a reference source attached to a range finder. An aperture between the lines is validated and stored. Distance to measure an angle is calculated. A spatial distance between the target points is calculated to determine pitching angles (psi) and rolling angles (theta) by applying a rule of sines or a law of cosines to a controller unit. A misalignment (e) of a segment on a horizontal or on a vertical gravity is deduced. An independent claim is also included for a range finder for measuring distances, lengths, surface areas and levels.
