Supply statements.
$$
\begin{aligned}
\text {Given:} & \mathrm{m} \angle \mathrm{AOB}=\mathrm{m} \angle 1 \\
& \mathrm{m} \angle \mathrm{BOC}=\mathrm{m} \angle 1
\end{aligned}
$$
Prove: $\overrightarrow{O B}$ bisects $\angle A O C$
GRAPH CAN'T COPY.
Statements
1. ?
2. ?
3. ?
4. ?
Reasons
1. Given
2. Substitution
3. Angles with equal measures are congruent
4. If a ray divides an angle into two congruent angles, then the ray bisects the angle