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**!nval!d_us3rnam3****Member**- Registered: 2017-03-18
- Posts: 6

Let the incircle of triangle $ABC$ be tangent to sides $\overline{BC}$, $\overline{AC}$, and $\overline{AB}$ at $D$, $E$, and $F$, respectively. Prove that triangle $DEF$ is acute.

I have tried proving that triangle DEF's angles were less than the opposite angles in triangle ABC, but that wasn't really complete. Can anyone help? Thanks!

Clean Clash Royale Jokes

Newb: I'm only arena 4 and I have a level 7 goblin barrel! Pro: How?

Newb: They have little 7's above their heads! Pro: *begins to rotflol*

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,666

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**!nval!d_us3rnam3****Member**- Registered: 2017-03-18
- Posts: 6

Thank you so much for helping!

Clean Clash Royale Jokes

Newb: I'm only arena 4 and I have a level 7 goblin barrel! Pro: How?

Newb: They have little 7's above their heads! Pro: *begins to rotflol*

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,666

Hi;

Hopefully, it will inspire you to learn more math and spread that to others. Welcome to the forum.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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