What is the length of this line?
Geometry
Level
1
Refer picture above. Two concentric circles of radius 4 and 5 are drawn around a center O. The line AB is tangent to the smaller circle at point C and meets the bigger circle at A and B. What is the length of the line AB ?.
5
6
7
8
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
ACO and BCO are right triangles as AB is a tangent at point C and hence the angle ACO is 90 degrees.
AO = 5;
OC = 4
Hence AC = BC =3. Hence the length of AB = 6.