# Typography of Geometry Problem 1353: Tangent Circles, Perpendicular
Diameters, Congruence, 30 Degrees, iPad Apps

### Proposition

The figure below shows
the circles of centers A and B tangent at C. Diameters EFBGH and CABD are
perpendicular and FG = DH. Prove that the angle MCN has a measure of 30
degrees.

See solution below

### 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 1353