**Circles ncert solutions Chapter 10 Exercise 10.2 Question 7**

**7.** Two concentric circles are of radii 5 cm and 3 cm. Find the length of the chord of the larger circle which touches the smaller circle.

**Solution:**

In

OA = 5 cm {Radius of bigger circle}

OC = 3 cm {Given radius of smaller circle}

{Radius (OC) is always perpendicular to the tangent (AB) of circle}

Therefore, is right angled triangle.

We cam use Pythagoras theorem to find AC.

**cm**

Similarly in , we can find length of BC which would be equal to 4 cm too.

**Therefore, length of AB = AC + BC = 4+4= 8 cm**