Question

if the radii of two concentric circles are 6 cm and 10 cm then find the length of a chord of the larger circle which is tangent to other

Answer 1

hello users 

solution
In triangle OAD and OBD
OA = OB = 10 cm (Radius of larger circle)
And
OD = 6 cm ( Radius of smaller circle)
And
AD and BD are the length of tangents
And
AB = length of chord of larger circle 

Here
Using Pythagoras theorem 
H² = B² + P² 

Here
AD = BD =√ (OA² - OD²)  = √ (OB² -  OD² )

=> AD = √ (10² - 6²)  

= √ (100 - 36)

= √ 64 

= 8 cm 

=> AD = BD = 8 cm 

Hence 
the length of chord = AB
= AD + BD 
= 8 cm + 8 cm
= 16 cm Answer

# hope it helps :)