The length of the chord of a circle is 8 cm and perpendicular distance between centre and the chord is 3 cm. Then the radius of the circle is equal to

AC = CB = 4 cm

OC = 3 cm

$herefore mathrm{OA}=sqrt{mathrm{OC}^{2}+mathrm{CA}^{2}}$

$=sqrt{3^{2}+4^{2}}=sqrt{9+16}=sqrt{25}=5 mathrm{~cm}$