Proof: perpendicular radius bisects chord  Summary and Q&A
TL;DR
Segment OD is proven to bisect segment AC in a circle with the help of congruent triangles.
Questions & Answers
Q: How is segment OD related to circle O?
Segment OD is a radius of circle O, meaning it connects the center O of the circle to a point D on its circumference.
Q: What information is given about segment AC?
It is stated that segment OD is perpendicular to segment AC, meaning they form a right angle where they meet.
Q: How are congruent triangles used in the proof?
Two congruent triangles (AMO and CMO) are established using the properties of the circle and the given right angle. If two triangles are congruent, then their corresponding sides are also congruent.
Q: How is it shown that OD bisects AC?
Because of congruence, it is proven that segment AM is congruent to segment CM. Therefore, point M, where OD intersects AC, must be the midpoint of AC, meaning OD bisects AC.
Summary & Key Takeaways

The video discusses a circle with point O as its center, segment OD as its radius, and segment AC as a chord.

The goal is to prove that segment OD bisects segment AC, meaning it intersects AC at its midpoint.

By establishing congruence between two triangles and using the properties of right triangles, it is shown that OD indeed bisects AC.