Answer
The three segments of the line $\overline{AB}$ are congruent.
We have trisected $\overline{AB}$
Work Step by Step
We can draw $\overline{AB}$
We can draw another line $\overline{AC}$
Using a compass, we can mark points $D, E,$ and $F$ such that $\overline{AD} \cong \overline{DE} \cong \overline{EF}$
We can connect points $B$ and $F$
We can draw parallel lines from points $D$ and $E$ to meet the line $AB$. Note that the angles at $D$ and $E$ are congruent to $\angle AFB$
Since these three blue lines are parallel, the three segments of the line $\overline{AB}$ are congruent.
We have trisected $\overline{AB}$
