Question

What special marks are used to show that segments are congruent

Answer 1

The special marks that are used to show that segments are congruent would be: Hashmarks.

Answer 2

Hatch marks or hash marks are used to show that segments are congruent

Explanation:

On any geometric figure, the congruency is denoted by hatch marks or hash marks.

For example - the notation to show the congruent sides of a triangle is done by using small tick marks, that show that the two sides are the same length or congruent.