Answer:
SAS Similarity
Explanation:
ΔOPQ similar to ΔRST
∠Q = ∠T
OQ : RT = 28 : 84 = 1 : 3
QP : TS = 16 : 48 = 1 : 3
The measures of two sides of ΔOPQ are proportional to the measure of two side of ΔRST and their included angles are congruent. The triangles are similar by SAS Similarity.