Question

Prove that Angle subtended at the center by equal chords are equal.

Answer 1

Given that : angle AOB & angle COD subtended at the centre.
prove that : Chords AB & CD are equal.
proof : In ∆s AOB & COD , we have
OA = AC. (radii of circle)
angle AOB = angle COD (given)
OB = OC. (radii of circle) therefore,, ∆AOB =~ ∆COD (By SAS rule)
AB =CD. (By C.P.C.T.)