3. One of the Lehmann's rules of plane tabling, is
Options
A. location of the instrument station is always distant from each of the three rays from the known points in proportion to their distances
B. when looking in the direction of each of the given points, the instrument station will be on the right side of one and left side of the other ray
C. when the instrument station is outside the circumscribing circle its location is always on the opposite side of the ray to the most distant point as the inter-section of the other two rays
Correct Answer: location of the instrument station is always distant from each of the three rays from the known points in proportion to their distances
4. One of the tacheometric constants is additive, the other constant, is
8. The difference of level between a point below the plane of sight and one above, is the sum of two staff readings and an error would be produced equal to
Options
A. the distance between the zero of gradient and the foot of the staff
B. twice the distance between the zero of graduation and the foot of the staff
C. thrice the distance between the zero of graduation and the foot of the staff