Two circles of radii `5 cm` and `3cm` intersect at two points and the distance between their centers is `4c mdot.`
Find the length of the common chord.

Options

A. `5 cm`
B. `4 cm`
C. `3 cm`
D. `6 cm`

Answer

D

Explanation

By Pythagoras theorem

`(5)^2 = (3)^2 + (4)^2`

`AO = 5cm`

`AO' = 3cm`

`OO' = 4 cm`

`(AO)^2 = (AO')^2 + (OO')^2`

In `/_ AOO' ` right angled triangle

`/_ AO'O = 90^@`

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