AB = 4.5
Explanation:
We can cross multiply the sides in order to find the length of AB. Make sure you don't go diagonal, so you can't do 3/6. You can do 3/4 and 3/x, then match it to the same pattern.
This is the one I chose...
Notice how I put them in the same order.
Now we can cross multiply...
= 4x
= 18
Divide by 4.
x = 4.5
The length of AB is 4.5.