Answer:
[tex]\boxed{\sf LM = 11}[/tex]
Step-by-step explanation:
According to trapezoid mid-segment theorem:
[tex]LM = \frac{QR+ST}{2}\\ Given \ that\ QR = 9, ST = 13[/tex]
[tex]\sf LM = \frac{9+13}{2}[/tex]
LM = 22/2
LM = 11