Question

Review Later
Question 10
If a line intersects two concentric circles with centre O at A, B,
C and D, then:
(Marks: 1
AB = CD
AB > CD
AB < CD
None of the above​

Answer 1

Answer:

We know that, OA=OD and OB=OC.

They are radius of respective circles.

In ΔOBC, we know that OB=OC, so ∠OBC=∠OCB

∴∠OCD=∠OBA

In ΔOAD, we know that OA=OD, so ∠OAD=∠ODA

Since, ∠OCD=∠OBA and ∠OAD=∠ODA, we get ∠AOB in ΔOAB is equal to ∠COD in ΔOCD.

∴ From SAS congruency, we can say that ΔOAB and ΔOCD are congruent.

So, AB=CD.