Using this boundary , a triangle of land north of the parallel was placed under Sudanese administration . It was because its inhabitants were closer to Khartoum than Cairo , both geographically and culturally . However , in 1902 the UK drew a separate `` administrative boundary , '' under which a triangle of land north of the parallel was placed under Sudanese administration , because its inhabitants were closer to Khartoum than Cairo , both geographically and culturally .