Answer
See the explanation below.
Work Step by Step
Two vectors are said to equal when they have the same direction and have the same magnitude or length.
The two line segments $\overrightarrow{AB}$ and $\overrightarrow{CD} $ will represent the same vector when the following conditions are satisfied.
a) The directions or unit vectors, $\dfrac{\overrightarrow{AB}}{|\overrightarrow{AB}|} $ and $\dfrac{\overrightarrow{CD}}{|\overrightarrow{CD}|}$ are equal.
b) When the two $\overrightarrow{AB}$ and $\overrightarrow{CD} $ will have equal magnitudes or lengths; that is,
$|\overrightarrow{AB}|=|\overrightarrow{CD}|$.
