Explanation:
Nigeria’s northern border stretches across two neighboring countries: Chad to the northeast and Niger to the north. These borders play an important role in trade, migration, and regional security. Niger shares a long stretch of land boundary with Nigeria, facilitating cultural and economic exchanges between the Hausa and Kanuri people across the border. Chad, though sharing a shorter border, is linked through Lake Chad, which is a source of water, fishing, and agricultural activities for communities on both sides.