Draw triangle ABC with vertices A(4,2), B(1,2) and C(1,4) using a scale of 1cm to represent I unit on each axis. Draw Triangle A’B’C’ under the reflection in the line y = 1, then triangle A’’B’’C’’ under a reflection in the line x = 0.

Answer 1

to reflect across y=1, (x,y) → (x,2-y)
across x=0 (the y-axis), (x,y) → (-x,y)
so make the needed adjustments.

Of course, if you're just doing the drawing as requested, simply flip your ruler across the indicated line. That's easy enough if you're using graph paper.