Online Geometry Problems

Online Geometry Problem 84. Contact Triangles Areas, Incircle, Excircle, Inradius, Exradius. Level: High School, College, Mathematics Education

In the figure below, given a triangle ABC, the incircle of radius r and the contact triangle of area S1, the excircle of radius ra and the contact triangle of area Sa. Prove that: formula to prove.

Geometry problem about triangle, incircle, excircle, contact triangles area
 


 

"A great discovery solves a great problem, but there is a grain of discovery in the solution of any problem. Your problem may be modest, but if it challenges your curiosity and brings into play your inventive faculties, and if you solve it by your own means, you may experience the tension and enjoy the triumph of discovery. Such expert experiences at a susceptible age may create a taste for mental work and leave their imprint on mind and character for a lifetime." George Polya, 1944 

 

HINTS:


1. See Problems 81, 82, 83.

Problem 81 Triangle, Incircle, Circumcircle, Area   Contact triangle area   Proposed Geometry Problem 83 Area of a contact triangle

 


 

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