learnohub
Question:
If a line intersects two concentric circles with center O at A ,B ,C and D, prove that AB=CD
Answer:

464039.PNG

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

Not what you are looking for? Go ahead and submit the question, we will get back to you.

learnohub

Classes

  • Class 6
  • Class 7
  • Class 8
  • Class 9
  • Class 10
  • Class 11
  • Class 12
  • ICSE 6
  • ICSE 7
  • ICSE 8
  • ICSE 9
  • ICSE 10
  • NEET
  • JEE

YouTube Channels

  • LearnoHub Class 11,12
  • LearnoHub Class 9,10
  • LearnoHub Class 6,7,8
  • LearnoHub Kids

Overview

  • FAQs
  • Privacy Policy
  • Terms & Conditions
  • About Us
  • NGO School
  • Contribute
  • Jobs @ LearnoHub
  • Success Stories
© Learnohub 2026.