Help on this Geometry Problem!

Prove that in ABC\triangle ABC, circle ABCABC is the nine-point circle of the extracentral triangle of ABCABC, that is, the triangle whose vertices comprise of the excenters.

You are free to share your proof below in the comments section.

#Geometry

Note by Alan Yan
5 years, 8 months ago

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Comments

ABC\triangle ABC is orthic triangle of the triangle whose vertices are ex-centers. To reverse the scenario, if we look at the orthic triangle of any given acute triangle, its angle bisectors are altitudes and sides of the reference triangle. This means that circumcirle of the orthic triangle is nine point circle of the reference triangle.

Maria Kozlowska - 5 years, 8 months ago

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Wait how do you know that ABC\triangle ABC is the orthic triangle?

Alan Yan - 5 years, 8 months ago

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Carefully read the second statement and make a good drawing. You can also check this website: orthic triangle

Maria Kozlowska - 5 years, 8 months ago
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