Prove that a diameter AB of a circle bisects all those chords which are parallel to the tangent at the point A.
Solution
According to question
Let us take a chord EF || XY
Here
( tangent at any point of the circle is perpendicular to the radius through the point of contact)
(Corresponding angles)
Thus AB bisects EF
Hence AB bisects all the chords which are parallel to the tangent at the point A.
Hence Proved