Question

Two concentric circles of radii a and b (a > b) are given. Find the length of
the chord of the larger circle which touches the smaller circle.
pls solve it as soon as possible​

Answer 1

Answer:

Hello

Step-by-step explanation:

Let O be the centre of the concentric circles. AB is the chord of the larger circle and tangent to the smaller circle at C.

Given, OC = b and OB = a.

AB is the tangent to the smaller circle.

∴ ∠OCB = 90° (Radius is perpendicular to the tangent at point of contact)

OD ⊥ AB,

In ΔOCB,

OB²= OC² + BC²

∴ BC² = OB²– OC²= a²– b²

BC = √a²-b²

AB = 2BC = 2√a²-b²

Thus, the length of chord AB is 2√a²-b²