Abstract. A Soddyian triangle is a triangle whose outer Soddy circle has degenerated
into a straight line. This paper examines some properties of Soddyian
triangles, including the facts that no Soddyian triangle can be right angled and
all integer Soddyian triangles are Heronian. A generating formula is developed
to produce all primitive integer Soddyian triangles. A ruler and compass construction
of a Soddyian triangle concludes the paper.