# Geometry Problem 1297: Arbelos, Semicircles, Diameters, Circle, Incircle, Tangent, Angle Bisector

The figure below shows an arbelos ABC (AB, BC, and AC are semicircles of centers O_{1}, O_{2}, and O).
The incircle of the arbelos is tangent to semicircles AC, AB, and BC at T,
T_{1}, and T_{2}, respectively. Prove that TB is the bisector of the
angle ATC.

### Poster of Problem 1297: Sketching, iPad, Typography, Art

## 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.

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