Solution
- The reflection of an object across a line implies that the distance between the object and the reflection line is the same as the distance between the image and the reflection line.
- This implies that if the distance between the point U and the reflection line ST is x, then, the distance between the reflection line and the image of U must be a distance of x as well.
- This is illustrated below:
- From the above, we can see that distance x is a perpendicular distance from point U to reflection line ST.
- However, we must not just assume that distance x lands at point J.
- We can however show that this is the case because of the SSS congruency. That is,
[tex]\begin{gathered} SU\cong SJ\text{ \lparen Given in the question\rparen} \\ UT\cong TJ\text{ \lparen Given in the question\rparen} \\ ST\text{ is a common side for both triangles SUT and SJT} \end{gathered}[/tex]
- Since both triangles are congruent, we can proceed to conclude that from line ST to point J is also a distance of x.
- Therefore, the image of U will coincide with J given that ST is the reflection line
