A spelunker is surveying a cave. She follows a passage 150m straight west, then 290m in a direction 45 east of south, and then 280 m at 30 east of…. A spelunker is surveying a cave. She follows a passage 150m straight west, then 290m in a direction 45? east of south, and then 280 m at 30? east of north. After a fourth unmeasured displacement, she finds herself back where she started.