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

Let O be the common center of two concentric circles and let AB be a chord of larger circle touching the smaller circle at P join OP

Since OP is the radius of the smaller circle to any chrod of the circle bisects the chord.

∴ AP=BP

In right ΔAPO we have

OA  

2

=AP  

2

+OP  

2

⇒25−9=AP  

2

⇒AP  

2

=16⇒AP=4

Now AB=2,AP=2×4=8[∵AP=PB]

hence the length of the chord of the larger circle which touches the smaller circle is 8cm.

Step-by-step explanation: