In figure, AB and CD are equal chords of a circle whose centre is O. If OM ⊥ AB and ON ⊥ CD, prove that ∠OMN = ∠ONM.
AB and CD are equal chords of a circle whose centre is O. When produced, these chords meet at E. Prove that EB = ED and AE = CE.
Given: AB and CD are equal chords of a circle whose centre is O. When produced, these chords meet at E.
To Prove: EB = ED and AE = CE.
Construction: From O draw OP ⊥ AB and OQ ⊥ CD. Join OE.
Proof: ∵ AB = CD | Given
∴ OP = OQ
| ∵ Equal chords of a circle are equidistant from the centre
Now in right ∆s OPE and OQE,
Hyp. OE = Hyp. OE | Common
Side OP = Side OQ | Proved above
PE - PB = QE - QD
EB = ED Proved.
BE + AB = ED + CD
AE = CE