Question: The centers of three circles, each with a radius R, are located on a straight line at points A, B and C. It is known that AB=BC=3. A fourth circle touches each of the three circles. Find all possible radii of the fourth circle if
a) R = 1 b) R = 2 c) R = 5
I am a bit confused as to how to begin solving the problem, as this is a trignometry question but I do not know where I can relate the triangle into the problem.