What is the primary purpose of locating an unknown point by intersection?

• A. Determine unknown position by intersecting azimuths from two known positions
• B. Determine distance between two known points
• C. Determine elevation at unknown point
• D. Convert grid azimuth to magnetic

Answer: (A)

Locating an unknown point by intersection relies on triangulation using two known positions. From each known point, you measure the azimuth toward the unknown point, creating a bearing line on the map. The unknown point must lie somewhere along each line, and the only place where both lines meet is the exact location of that point. This intersection fixes the horizontal position because it satisfies both directional constraints simultaneously, giving a precise fix when measurements are accurate.

This method works because bearings from different references converge at the common point, turning directional information into a location. The other ideas describe different tasks: measuring the distance between two known points, determining elevation, or converting a grid azimuth to magnetic—none of these uniquely fixes the unknown’s position on the map.