Question:
The congruent circles with centres O and O’ intersect at two points A and B. Then, ∠AOB = ∠AO’B.
Solution:
True
Join AB, OA and OB, O’A and BO’.
In ΔAOB and ΔAO’B,
OA = AO’ [both circles have same radius]
OB = BO’ [both circles have same radius]
and AB= AB [common chord]
ΔAOB = ΔAO’B [by SSC congruence rule]
=> ∠AOB = ∠AO’B [by CPCT]