we know that
Translations of geometric figures in the coordinate plane can be determined by translating the x- and y-coordinates of points. The translation is an isometric transformation (not changes the size of the figure)
so
vertex
--------> 
<u>Find the rule in the x-coordinate</u>

x--------> x+2
<u>Find the rule in the y-coordinate</u>

y--------> y+1
<u>The translation rule is </u>

<u>Verify vertex B</u>
------->
------>
-------->
------> is ok
<u>Verify vertex C</u>
------->
------>
-------->
------> is ok
The three vertices have the same rule, therefore the triangles are congruent
<u>the answer is</u>
The translation rule is
