Two circles of radii 12.5 cm and 7.5 cm are concentric. The length of a chord of the outer circle which touches the inner circle is
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Correct answer: C
Explanation
Given:
Outer radius R = 12.5 cm, Inner radius r = 7.5 cm
According to the formula:
Length of the chord = 2√(R² − d²), where d = distance from the center = r
= 2√(12.5² − 7.5²)
= 2√(156.25 − 56.25)
= 2√100
= 2 × 10
= 20 cm