Determine whether qr is parallel to st

The correct answer is: 3. QR ∦ ST    4. QR ║ ST

Step-by-step explanation:

If the PST and PQR triangles are similar, then the corresponding sides are proportional. We will check that:

PS : PQ = PT : PR  ⇔ PS / PQ = PT / PR = k

3.

10/4 = 8/3 => 5/2 = 8/3

When we multiply the both fractions to get same denominators we get

15/6 ≠ 16/6

the corresponding sides are not proportional and triangles PST and PQR are not similar and QR ∦ ST => QR is not parallel to ST

4.  27/22 = 43.2/35.2 = 1.2272727 = 1.2(27)

the corresponding sides are proportional and triangles PST and PQR are similar and QR ║ ST => QR is parallel to ST

God with you!!!