Wednesday, January 2, 2013

Problem 841: Triangle, Medians, Centroid, Circumcenters, Perpendicular, Congruence, Similarity

Geometry Problem
Level: Mathematics Education, High School, Honors Geometry, College.

Click the figure below to see the complete problem 841.

Online Geometry Problem 841: Triangle, Medians, Centroid, Circumcenters, Perpendicular, Congruence, Similarity

2 comments:

  1. ∵ HO4 perpendicular bisects BG
    ∵ MO6 perpendicular bisects GE
    ∴ HM//BE and HM=BE/2

    Similarly, HN=AD/2.

    ∵ ∠NHO2=∠MHO4=90°
    ∴ ∠NHO4=∠MHO2
    ∴ ΔHNO4~ΔHMO2
    ∴ HM/HO2=HN/HO4
    ∴ HO4×HM=HO2×HN

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  2. Note o2o6 perpendicularly bisect GE ; o3o4 perpendicularly bisect of GB.
    Say they bisect at points P and Q respectively. So, PQ = BE/2.
    Easy observe that HMPQ forms a rectangle. HM = PQ

    For the next part, HO4.HM represent double of triangle area of HMO4. And HO2.HN represent double of triangle area of HNO2.
    By affine transformation which preserves area, transform the triangle into an equilateral ones, and it is proved

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