Right Angles and Foot of Perpendicular on the Lines | Chain Surveying | Surveying
This article throws light upon the top five instruments that are used for setting out right angles and finding the foot of perpendicular from the object on the lines. The instruments are: 1. Cross Staff 2. Optical Square 3. Prism Square 4. Offset Rod 5. Measuring Tape. Instrument # 1. Cross-Staff: It is generally found in two patterns: (i) Open [...]