Respuesta :

Answer:

10

Step-by-step explanation:

Set up as a proportion:

[tex]\frac{QR}{QP}=\frac{BA}{BC}[/tex], insert given values

[tex]\frac{?}{12}=\frac{30}{36}[/tex], cross multiple

36*?=30*12

36*?=360, divide both sides by 36 to get the missing side (?) by itself

?=10