Reciprocal Track

A direction opposite another is its reciprocal. Just as south is 180° from north, reciprocal directions are 180° apart. To find the reciprocal, add 180° if the initial direction is less than 180°, or subtract 180° if it’s more. For example, the reciprocal of 021° is 201° (021 + 180 = 201). The reciprocal of 333° is 153° (333 – 180 = 153).