Answer:
x=3.5
Step-by-step explanation:
We can use proportions to solve this problem. Put the side of one triangle over the same side of the other triangle.
6 4.2
------ = ----------
5 x
Using cross products
6x = 5*4.2
6x =21
Divide by 6
6x/6 = 21/6
x=3.5
