Subcontests
(3)a B,I,G problem
The incircle of a triangle ABC touches the sides AB,BC,CA at points D,E,F respectively. The line through A parallel to DF meets the line through C parallel to EF at G.
(a) Prove that the quadrilateral AICG is cyclic.
(b) Prove that the points B,I,G are collinear. Diophantine - Find all (a,b,p)
Find all triples of positive integers (a,b,p) with a,b positive integers and p a prime number such that 2a+pb=19a