Online Geometry Problems

Geometry Problem 85. Contact Triangles Areas, Incircle, Excircle, Contact Triangles. High School, College, Math Education

In the figure below, given a triangle ABC, S1 is the area of contact triangle of the incircle, Sa, Sb, and Sc are the areas of the contact triangles of the excircles. Prove that: \(\dfrac{1}{S_1}=\dfrac{1}{S_a}+\dfrac{1}{S_b}+\dfrac{1}{S_c}\).

Math problem about contact triangles, area, incircle, excircle



1. See Problems 82, 83, 84.

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