Circles touching internally

Jun 2014
2
0
India
Two circles having radii 9 c.m and 5 c.m touch each other internally. What is the distance between the centres of the circles. PLEASE EXPLAIN
 

greg1313

Forum Staff
Oct 2008
8,008
1,174
London, Ontario, Canada - The Forest City
Since the two circles are tangent, the radius of the smaller circle lies on the radius of the larger circle, hence the distance between the centers of the two circles is 9 - 5 = 4 cm.