RA = 5 (slider from 0 to 5, step 0.1)
CentroTerra = Intersect(xAxis, yAxis)
a = Circle(CentroTerra, RA)
RB = 3.7 (slider from 0 to 5, step 0.1)
RC = 1.4 (slider from 0 to 5, step 0.1)
b = Circle(CentroTerra, RB)
c = Circle(CentroTerra, RC)