Geometry Problem 53: Tangent Circles, Angle Bisector, Typography, iPad Apps

Proposition

The figure shows a right triangle ABC with the altitude BD. Lines DE and DF are perpendicular to AB and BC, respectively, r, r₁, and r₂ are the inradii of the triangles ABC, AED, and DFC respectively. Prove that r₁ + r₂ = r.

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Geometric Art using Mobile Apps

Geometric art is a form of art based on the use and application of geometric figures. A geometric figure is any set or combination of points, lines, surfaces and solids.

A mobile app or mobile application software is a computer program designed to run on smartphones and tablet computers.

See also:
Original problem 53.