Question 54353
When you reflect something about the y axis, you want the point to have the same heighth, but be equally far on the other side of the y-axis.  We can do that by changing the sign of x and keeping y the same.(x,y) would be (-x,y) and (-x,y) would be (x,y)
:
R(-2,4) would be (2,4)
S(2,0) would be (-2,0)
T(.1,.1) would be (-.1,.1)
:Plot the points and see that it's the same triangle flipped on it's side about the y-axis.  I can't graph triangles on this or I'd show you.
Hope that helps.