44) What is the true distance between two points?
Measured distance = 720 m.
Length of chain = 20 m.
Error in chain = (+) 40 cm.

45) Find the true distance (Mean incorrect length of chain, L' = 20.3 m length of chain, L = 20 m, measured distance = 3000 m).

46) What formula is used to find the area by a planimeter?