Q. Out of two concentric circles,the radius of the outer circle is 5 cm and the chord AC of length 8 cm is tangent to the inner circle.Find the radius of the inner circle.

Asked by sambitgenius2005 | 24th Apr, 2019, 08:03: PM

Expert Answer:

 
 
 
 
 
 
 
From the figure,
 
Chord AB = 8 cm
OC is perpendicular to the chord AB
AC = CB = 4 cm
In right triangle OCA
OC2 + CA2 = OA2
OC2 = 52 - 42 = 25 - 16 = 9 
OC = 3 cm
 

Answered by Sneha shidid | 25th Apr, 2019, 09:47: AM