If two equal chords of a circle intersect, then prove that their segments are equal. [3 MARKS]
Concept: 1 Mark
Application: 2 Marks
Given: A circle with center O. Its two equal chords AB and CD intersect at E.
To prove: AE = DE and CE =BE
Construction: Draw OM⊥AB and ON⊥CD. Join OE.
Proof: In ΔOME and ΔONE
OM=ON (Equal chords of a circle are equidistant from the centre)
OE=OE (Common)
∴ ΔOME≅ΔONE (R.H.S)
⇒ME=NE (C.P.C.T)
⇒AM+ME=DN+NE (∵AM=DN=12AB=12CD)
[Perpendicular from centre divide the chord into two equal parts]
⇒AE=DE
⇒AB−AE=CD−DE (GivenAB=CD)
⇒BE=CE