Mathematics for IGCSE & O level - Circle Theorems (Section 1 - No. 45)
If a line from the center of a circle meets a chord at right angles, what does it do to the chord?
It bisects the chord.
It is parallel to the chord.
It is longer than the chord.
It has no effect on the chord.
解释
A line from the center perpendicular to a chord bisects the chord.