For use with the British grid, the map area should be which of the following shapes and orientations?

• A. Large and square, with long axis East-West
• B. Small and circular, with center at the equator
• C. Small, long and narrow, with long axis in direction of meridian or parallel
• D. Medium, rectangular, oriented diagonally

Answer: (C)

In a British National Grid setup, the projection used is a transverse Mercator style, which keeps distortion minimal when the area being mapped is a narrow strip that runs in a north–south direction. That means the map area should be small and long and narrow, with its long axis aligned with a line of longitude (a meridian). Keeping the shape this way confines distortion to a small width and preserves more accurate distances and directions across the area. A large square would widen distortion, a circular area isn’t practical for a grid system, and a diagonally oriented rectangle wouldn’t align with the projection’s natural grid orientation, complicating measurements and grid references. This is why the best choice describes a small, long, narrow map area oriented along the meridian.