From the picture, the corresponding parts are:
RT ≅ WU
TS ≅ VW
RS ≅ VU
Reflecting RST across y-axis, we get:
R(-4, -3) → R'(4, -3)
S(0, -3) → S'(0, -3)
T(-3, 0) → T'(3, 0)
Translating R'S'T' 4 units up and 2 units left, we get:
R'(4, -3) → (4 - 2, -3 + 4) → U(2, 1)
S'(0, -3) → (0 - 2, -3 + 4) → V(-2, 1)
T'(3, 0) → (3 - 2, 0 + 4) → W(1, 4)
RST is mapped onto UVW reflecting RST across y-axis, and then translating it 4 units up and 2 units left