Question

If triangle XYZ is reflected across the line y = 1 to create triangle X'Y'Z', what is the ordered pair of X'? 

(1, −5)  
(1, −3)

 
(1, 3)  
(1, 5)

Answer 1

x is 4 below y =1 so the image will be 4 above y = 1. The x coorinadte will be the same.

So x' is (1,5) answer

D

Answer 2

Consider triangle XYZ with vertices at points X(1,-3), Y(3,0) and Z(-1,-1). If triangle XYZ is reflected across the line y = 1, then the rule of reflection is

(x,y)→(x,-y+2).

The image X' of point X will have coordinates according to the given rule:

X(1,-3)→X'(1, -(-3)+2)=X'(1,5).

Answer: correct choice is D.