# Geometry Problem 1305:

### Triangle, Circumcircle, Angle Bisector, Arc, Perpendicular, Area

The figure below shows a triangle ABC with the circumcircle of center O. The bisector of the angle A cuts BC at D and the arc BC at E. If DH is perpendicular to AC, prove that the area of the triangle AEH is half the area of the triangle ABC. See also: Art of Problem 1305, Typography using iPad Apps.

## Geometric Art using Mobile Apps

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

### Hyperbolic Kaleidoscope, Poincare Disk Model

Poincare disk model is a model of 2-dimensional hyperbolic geometry in which the points of the geometry are inside the unit disk, and the straight lines consist of all segments of circles contained within that disk that are orthogonal to the boundary of the disk, plus all diameters of the disk. Read more.

### Problem 1305 in Motion using Mobile Apps, iPad

Click on the figure below.

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