HMMT 十一月 2010 · 冲刺赛 · 第 16 题
HMMT November 2010 — Guts Round — Problem 16
题目详情
英文原题
- [ 9 ] Triangle ABC is given in the plane. Let AD be the angle bisector of ∠ BAC ; let BE be the altitudefrom B to AD , and let F be the midpoint of AB . Given that AB = 28 , BC = 33 , CA = 37, what isthe length of EF ?
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解析
英文解析
- [ 9 ] Triangle ABC is given in the plane. Let AD be the angle bisector of ∠ BAC ; let BE be the altitudefrom B to AD , and let F be the midpoint of AB . Given that AB = 28 , BC = 33 , CA = 37, what isthe length of EF ?
Answer: 14 4 ABE is a right triangle, and F is the midpoint of the hypotenuse (and therefore thecircumcenter), so EF = BF = AF = 14.