All the “parts” of a circle, such as the radius, the diameter, etc., have a relationship with the circle or another “part” that can always be expressed as a theorem. The two theorems that deal with chords and radii (plural of radius) are outlined below.
1. If a radius of a circle is perpendicular to a chord, then the radius bisects the chord.
Here’s a graphical representation of this theorem:
2. In a circle or in congruent circles, if two chords are the same distance from the center, then they are congruent.