We will calculate the radius using Pythagoras theorem
[tex]\begin{gathered} \text{hypotenus}^2=opposite^2+adjacent^2 \\ \text{hypotenus}=\text{radisu r} \\ \text{opposite}=6\operatorname{cm} \\ \text{adjacent}=4\operatorname{cm} \end{gathered}[/tex]By substitution we will have
[tex]\begin{gathered} r^2=6^2+4^2 \\ r^2=36+16 \\ r^2=52 \\ r=\sqrt[]{52\text{ cm}} \end{gathered}[/tex]Let CF=x, To calculate CF, WE WILL UE THE PYTHAGORAS THEOREM ALSO
[tex]\begin{gathered} \text{hypotenus}^2=opposite^2+adjacent^2 \\ \text{Hypotenus}=\sqrt[]{52\operatorname{cm}} \\ \text{opposite}=x \\ \text{adjacent}=4\operatorname{cm} \end{gathered}[/tex]By substitution we will have that,
[tex]\begin{gathered} (\sqrt[]{52)^2}=x^2+4^2 \\ 52=x^2+16 \\ x^2=52-16 \\ x^2=36 \\ x=\sqrt[]{36} \\ x=6\operatorname{cm} \end{gathered}[/tex]Hence,
CF=6cm
The right answer is OPTION A