Question

Triangle ABC is reflected to form triangle A'B'C'.

Answer 1

When we reflect a point across an axis, the distance between the point and the axis stays the same, but is flipped to the opposite side. 

We know that the coordinates of point A are (4,1), the coordinates of point B are (6,3), and the coordinates of point C are (2,4).  

In this case, Triangle ABC is a reflection of point A'B'C' across the y-axis. 

=  reflection across the y-axis