Two circles of radii 10 cm and 8 cm intersect each other, and the length of the common chord is 12 cm. The distance between their centers will be
The correct option is B: 8+2√7 cm
OA=10 cm,CA=8 cm and AB=12 cm
AD=12AB=6 cm (⊥ from the center of the circle bisects the chord)
In right triangle OAD, we have
OA2=OD2+AD2
⇒102=OD2+62
⇒OD2=√100−36=8 cm
Again, in right triangle ADC, we have
AC2=AD2+DC2
⇒82=62+DC2
⇒DC=√64−36=√28=2√7 cm
∴OC=OD+DC=8+2√7
Hence, the distance between the centers is (8+2√7) cm