Let A be at 0,0 &AB lie on x axis then B is [3,0]
The segment is translated 7 units down and 8 units to the right
A1 =[0+8,0–7]= [8,-7] ; B1 = [3+8,0–7] =[11 ,-7]
A1B1 = √ [11–8]^2 +[-7-(-7)^2 = √ 9+0 =3
Answer: The length of the image after the translation is the same as the previous value of 3 units. No change in length
Hope this helps