$\"\"$

Two sides/segments are Congruent if they have the exact same length.

From the figure the lengths of segments are:

$\"\"$ \ \

$\"\"$ (Apply Distributive property: $\"\"$ )

$\"\"$

$\"\"$ (Apply Distributive property: $\"\"$ ) $\"\"$

Compare the lengths of segments and they have same lengths.

So, segments $\"\"$ and $\"\"$ are congruent. $\"\"$

Segments $\"\"$ and $\"\"$ are congruent.