Answer
The order in which the points of the triangles are listed identify the corresponding parts.
Work Step by Step
ΔMNP∼ΔRST
The triangles have the same angle measurements and same side length ratios, but different side length measurements. The points/letters on the triangles indicate how these two similar triangles are drawn to correspond with each other.
M and R, N and S, and P and T correspond with each other.
The triangles are drawn so that these points line up to have the the same angle measurements and side length ratios, making them similar.