4 circles + 2 lines = 6 steps (par 6)

Consider the midpoint M of [math]\overline{AB}[/math][br][math]\triangle ABE[/math] and [math]\triangle MBC[/math] are similar, and [math]\overline{AB}[/math] = 2[math]\overline{AM}[/math], so [math]\overline{AE}[/math] = 2[math]\overline{CM}[/math][br][math]\triangle AFE[/math] and [math]\text{\triangle}MFD[/math] are similar, and [math]\overline{MD}[/math] = [math]\overline{CM}[/math], so [math]\overline{AF}[/math] = 2[math]\overline{FM}[/math]