Question

Prolongation of chain line across an obstruction in chain surveying is done by -

• A. All options are correct
• B. Solution of triangles
• C. Making angular measurements
• D. Drawing perpendiculars with a chain

Answer 1

The correct option is A All options are correct

Prolongation of chain line across an obstruction in chain surveying is done by following methods.

(a) Drawing perpendicular with a chain



(b) Making angular measurment

• Let DAB be a chain line
• Lay off AC of any convenient length, perpendicular to AB
• Lay off DC perpendicularly to BC

$\frac{AB}{AC}=\frac{AC}{AD}$

$AB=\frac{A{C}^2}{AD}$