WOLFRAM|DEMONSTRATIONS PROJECT

The Semiperimeter and Tangents to Excircles

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AB
≈
9.40
AC
≈
8.03
BC
≈
7.08
p
≈
12.26
AD
≈
12.26
AE
≈
12.26
Let ABC be a triangle. Construct the excircle opposite A and let D and E be the intersections of the extensions of AB and AC with the excircle. Let
p
be the semiperimeter of ABC. Then
p
= AD = AE.