If side QU is similar to side RT, QS equals 4
What is line QS
If side QU is similar to side RT,
Then,
SU is similar to QS
ST + TU : QR + RS
ST : RS = TU : QR
4 : 2 = 4 : x
4/2 = 4/x
cross product
4 ×x = 4 × 2
4x = 8
x = 8/4
x = 2
Therefore,
QS = QR + RS
= 2 + 2
= 4