17. What do you mean by Reduction to centre: If the true station were occupied by computing the…

17. What do you mean by Reduction to centre: If the true station were occupied by computing the corrections and apply them algebraically to the observed values is generally known as reduction of centre . 18. What are the Equipments used for base line measurement: Marking stakes or tripod Straining device Supporting stakes or tripod Steel tape Six number of thermometer. 19 What are the Two types of Trigonometrically leveling: Plane Trigonometrical levelling Geodetic Trigonometrical leveling