Let
![ABC](/media/m/a/c/7/ac75dca5ddb22ad70f492e2e0a153f95.png)
be a triangle, and
![I](/media/m/3/8/6/38689d6affa9ba35368ca4d3d76ea147.png)
its incenter. Consider a circle which lies inside the circumcircle of triangle
![ABC](/media/m/a/c/7/ac75dca5ddb22ad70f492e2e0a153f95.png)
and touches it, and which also touches the sides
![CA](/media/m/a/a/e/aaec86bc003cfdb64d54116a4cabd387.png)
and
![BC](/media/m/5/0/0/5005d4d5eac1b420fbabb76c83fc63ad.png)
of triangle
![ABC](/media/m/a/c/7/ac75dca5ddb22ad70f492e2e0a153f95.png)
at the points
![D](/media/m/7/0/0/7006c4b57335ab717f8f20960577a9ef.png)
and
![E](/media/m/8/b/0/8b01e755d2253cb9a52f9e451d89ec11.png)
, respectively. Show that the point
![I](/media/m/3/8/6/38689d6affa9ba35368ca4d3d76ea147.png)
is the midpoint of the segment
![DE](/media/m/a/c/d/acdf3f4d3c794d9a897484e9d216f5ec.png)
.
%V0
Let $ABC$ be a triangle, and $I$ its incenter. Consider a circle which lies inside the circumcircle of triangle $ABC$ and touches it, and which also touches the sides $CA$ and $BC$ of triangle $ABC$ at the points $D$ and $E$, respectively. Show that the point $I$ is the midpoint of the segment $DE$.