AstroSpeedrunSearch
2015

From Lima to Yogyakarta

Round
Theory
Points
Not given
Level
Silver
Taught in
Section 1.5

Adapted from IOAA 2015 (Magelang), theory problem 15. We have restated it in our own words and kept the original data. The solution was last checked on 15 October 2026.

An aircraft flies from Lima in Peru (12°02′ S, 77°01′ W) to Yogyakarta in Indonesia (7°47′ S, 110°26′ E) along the shortest route over Earth's surface. Find the latitude of the most southerly point of the route.

AnswerThe route reaches latitude 69°38′ S, far south of both cities.

This problem also appears among the olympiad problems of Section 1.5, The astronomical triangle, which teaches the ideas it uses. Equation and figure numbers refer to the course.