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Two circles of radii 10 cm and 8 cm intersect and the length of the common chord is 12 cm. Then the distance between their centres is
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- 10 cm
- 8 cm
- 13.3 cm
- 15 cm
- 10 cm
Correct Option: C
As per the given in question , we draw a figure of two circles with centres O and O' , 
Given that , AB = 12 cm
AC = BC = 6 cm
OA = 10 cm
From ∆ AOC,
∴ OC = √OA² - AC²
OC = √10² - 6² = √100 - 36
OC = √64 = 8 cm
Again, in ∆ ACO',
AO' = 8 cm
∴ O'C = √8² - 6²
O'C = √64 - 36 = √28 = 5.3 cm
∴ OO' = OC + CO'
OO' = 8 + 5.3 = 13.3 cm
