we have that
The coordinates of the pre-image and the image of the triangle are
[tex]A(-1,4)----->A'(3,4)[/tex]
[tex]B(-1,10)----->B'(3,10)[/tex]
[tex]C(3,6)----->C'(7,6)[/tex]
so
The rule of the translation is
[tex](x,y)-------> (x+4,y)[/tex]
That means
The translation is [tex]4[/tex] units to the right
therefore
the answer is
The translation is [tex]4[/tex] units to the right
