# Typography of Geometry Problem 1373: Isosceles Triangle, Exterior Cevian, Inradius,
Exradius, Altitude, iPad Apps

### Proposition

In the figure below,
ABC is an isosceles triangle (AB = BC) with altitude BE = h. D is a point on CA
extended, r_{1} is the inradius of the triangle DAB and r_{2} is the exradius of
the triangle DBC corresponding to BC. Prove that r_{1} + r_{2}
= h.

*BD is called an exterior
cevian of triangle ABC.*

See also:

Original problem 1373.

### Geometric Art using iPad or 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
1373.