WOLFRAM|DEMONSTRATIONS PROJECT

The Area of the Excentral Triangle

​
p
≈
17.84
r
≈
3.54
A
≈
63.19
p
×
r
≈
63.19
Let
A
be the area of the triangle formed by the excenters of a triangle with perimeter
p
and circumradius
r
. Then
A=p×r
.