They are equidistant from the center of the circle.
What the word congruent and circle have in common is that circles have a congruent radii. All of the radii in a single circle is congruent to each other.
true, because both distances of the chord are congruent
They must be congruent.
Yes, all of the radii in a single circle are congruent.
Yes, there can be congruent arcs on a circle. Arcs which subtend the same angle at the center are considered as congruent.
In the same circle, or in congruent circles, two minor arcs are congruent if and only if their corresponding chords are congruent.
No they can not be congruent because they are different shapes.