# The Contact Triangle and Two Other Subtriangles

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Let ABC be a triangle. Let A', B', and C' be the vertices of the contact triangle (the triangle with vertices where the incircle touches the sides of ABC). If , , and , then .

Contributed by: Jay Warendorff (March 2011)

After work by: Antonio Gutierrez

Open content licensed under CC BY-NC-SA

## Snapshots

## Details

The statement of the theorem is in Problem 110. Contact Triangle, Area, Incircle.

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