How do you indicate congruent segments in a diagram?

by placing identical markings on each side, often a single stroke for one set of equal sides, a double stroked bar for the second set etc.

Here is a diagram showing such markings.
Also notice how they mark equal angles, re your other posting.

http://img.sparknotes.com/figures/B/bc520655c299866d34385c463a8e56f8/isotrap.gif

To indicate congruent segments in a diagram, you typically use tick marks or notation. Here's how you can do it step by step:

1. Start by identifying the segments that are congruent in your diagram. Congruent segments are segments that have the same length.

2. Once you've identified the congruent segments, you can use tick marks to indicate their congruency. Tick marks are short perpendicular lines added to both ends of the segments. These tick marks should be the same length.

3. Place the tick marks on the congruent segments by extending the lines of the segments slightly past their endpoints. Ensure that the tick marks on the congruent segments have the same length.

4. If the diagram is complex or if there are many congruent segments, you can use a notation to indicate the congruence. For example, you can label the congruent segments with the same letter or number on top of them. This notation allows you to refer to the congruent segments easily.

By using tick marks and notation, you can clearly indicate congruent segments in a diagram.