
Co-ordinates of focus of parabola will be S=(a,0)=(1,0).
Now, length of latus-rectum =4.
So, length of semi latus-rectum =2.
Also, ∠LSC1=90∘
Now, radius of circle LC1=25
Now, applying pythagoras theorem in △LSC1,
(LC1)2=(C1S)2+(LS)2
⇒(C1S)2=(LC1)2−(LS)2=(25)2−(2)2=16
⇒C1S=16=4
∴C1C2=2C1S=2×4=8.