# Geometry Problem 40 with Solution:

## Triangle, Incenter, Excenter, 40, 60, 80 Degrees

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In
a
triangle ABC, the
angles
A and B measure 80 and 40 respectively, I
is the
incenter and E the
excenter. AB and CE meet at D. If BC = a, AC = b and CI = d,
prove
that: \(DE= \dfrac{a \cdot (a-b)}{d}\).

See solution below

## Poster of problem 40

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