HMMT 二月 2003 · 冲刺赛 · 第 10 题
HMMT February 2003 — Guts Round — Problem 10
题目详情
英文原题
- [7] Suppose that A, B, C, D are four points in the plane, and let Q, R, S, T, U, V be therespective midpoints of AB, AC, AD, BC, BD, CD . If QR = 2001 , SU = 2002 , T V =
2003, find the distance between the midpoints of QU and RV .
2 2 2 2 2
解析
英文解析
- Suppose that A, B, C, D are four points in the plane, and let Q, R, S, T, U, V be therespective midpoints of AB, AC, AD, BC, BD, CD . If QR = 2001 , SU = 2002 , T V =
2003, find the distance between the midpoints of QU and RV .
Solution: 2001
This problem has far more information than necessary: QR and U V are both parallelto BC , and QU and RV are both parallel to AD . Hence, QU V R is a parallelogram,
and the desired distance is simply the same as the side length QR , namely 2001. (Seefigure, next page.)
2 2 2 2 2