Q=9
Step-by-step explanation:
if we get the bottom lengths of both triangles and divide them by eachother we can find the scale factor. so 12/4=3 meaning the scale factor is 3 meaning the bigger triangle is 3 times bigger so if we have the smaller version of the length of Q we just have to multiply 3 by 3 to get the enlarged version so Q=9inch
(its a lot of words but i wanted to make sure you understand)