Question

two concentric circles are of radii 5 cm & 3 cm
find length of chord of larger circle which touches smaller
circle​

Answer 1

Answer:

8cm

Step-by-step explanation:

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

Answer 2

hi mate your answer

Draw two concentric circles with the centre O. Now, draw a chord AB in the larger circle which touches the smaller circle at a point P as shown in the figure below.

From the above diagram, AB is tangent to the smaller circle to point P.

∴ OP ⊥ AB

Using Pythagoras theorem in triangle OPA,

OA2 = AP2 + OP2

=> 52 = AP2 + 32

=> AP2 = 25 – 9 = 16

=> AP = 4

OP ⊥ AB

Since the perpendicular from the centre of the circle bisects the chord, AP will be equal to PB

So, AB = 2AP = 2 × 4 = 8 cm

Hence, the length of the chord of the larger circle is 8 cm.