David drew pqr and stu so that p s, pr = 12, su = 3, pq = 20, and st = 5. are pqr and stu similar? if so, identify the similarity postulate or theorem that applies.

PR : PQ = 12 : 20 = 3 : 5
SU : ST = 3 : 5
and ∠ P = ∠ S
SAS: side, angle, side.
The triangles are similar if:
- the ratio between 2 sides of one triangle is the same as the ratio between 2 sides of another.
- the included angles are equal.
Triangles PQR and STU are similar.

The answer is 1 because you have to flip the sign when dividing by negative number and 3