PUMaC 2010 · 几何（B 组） · 第 4 题
PUMaC 2010 — Geometry (Division B) — Problem 4
题目详情
- Unit square ABCD is divided into four rectangles by EF and GH , with BF = . EF is 4 parallel to AB and GH parallel to BC . EF and GH meet at point P . Suppose BF + DH = F H , calculate the nearest integer to the degree of ∠ F AH .
解析
- Square ABCD is divided into four rectangles by EF and GH . EF is parallel to AB and GH parallel to BC . EF and GH meet at point P . Suppose BF + DH = F H , calculate the nearest integer to the maximal value of the degree of ∠ F AH . 1 [Answer] 45 [Solution] Rotate 4 ABF counterclockwise 90 degrees to 4 ADM and we get AF H and AM H 1 ◦ congruent (SSS congruency). Hence ∠ F AH = ∠ F AM = 45 . 2