Question

Two concentric circles are radii 5 cm and 3 cm are drawn. Find the length of the larger circle which touches the smaller circle​

Answer 1

Answer:

Let O be the centre of the concentric circle of radii 5 cm and 3 cm respectively. Let AB be a chord of the larger circle touching the smaller circle at P.

Then

AP=PB and OP⊥AB

Applying Pythagoras theorem in △OPA, we have

OA

2

=OP

2

+AP

2

⇒25=9+AP

2

⇒AP

2

=16⇒AP=4 cm

∴AB=2AP=8 cm