Answer:
[tex]\rm 10.9 cm [/tex]
Step-by-step explanation:
Given that :-
- A chord of a circle is 18 cm long.
- It is 6.3 cm from the centre of the circle.
And we need to find out the radius of the circle.
[tex]\text{ Theorem :-}[/tex]
- Perpendicular from the centre of circle , to the chord , bisects the chord .
Using Pythagoras Theorem :-
[tex]\implies \rm OA^2= AB^2+OB^2\\\\\rm\implies OA^2= (6.3 cm)^3+(9cm)^2\\\\\rm\implies OA^2=
120.69 \\\\\implies\boxed{\rm OA = 10.9 cm }[/tex]
Hence the radius is 10.9 cm
