33. A spelunker is surveying a cave. She follows a passage 180 m straight west, then 210 m in a direction east of south, and then 280 m at east of north. After a fourth unmeasured displacement, she finds herself back where she started

 33. A spelunker is surveying a cave. She follows a passage 180 m straight west, then 210 m in a direction east of south, and then 280 m at east of north. After a fourth unmeasured displacement, she finds herself back where she started. Use a scale drawing to determine the magnitude and direction of the fourth displacement. (See also Problem 1.73 for a different approach to this problem.)