If a chord of a circle of the radius 5 cm. is a tangent to a circle of radius 3 cm., both the circle being concentric, then the length of the chord is - 5 सेमी. त्रिज्या वाले एक वृत्त की जीवा, 3 सेमी. त्रिज्या वाले एक अन्य वृत्त की स्पर्श रेखा है। तद्नुसार यदि दोनों वृत्त संकेन्द्रीय हो तो उस जीवा की लम्बाई है -

The chord of the larger circle (radius 5 cm) touches the smaller circle (radius 3 cm) at one point. The perpendicular from the common center to the chord equals the smaller radius = 3 cm. This forms a right triangle with: half-chord (one leg), 3 cm (other leg), and 5 cm (hypotenuse). By Pythagoras: (half-chord)^2 + 3^2 = 5^2 → (half-chord)^2 = 25 - 9 = 16 → half-chord = 4 cm. Full chord length = 2 × 4 = 8 cm.